@article{wan_luo_kim_chung_chang_yamashita_jiang_2022, title={<p>The overpoling effect of alternating current poling on rhombohedral Pb(Mg1/3Nb2/3)O-3-PbTiO3 single crystals</p>}, volume={120}, ISSN={["1077-3118"]}, DOI={10.1063/5.0086057}, abstractNote={The overpoling effect of alternating current poling (ACP) was studied on [001]-orientated rhombohedral Pb(Mg1/3Nb2/3)O3-0.26PbTiO3 (PMN-0.26PT) single crystals. Our experimental results showed that the property enhancement from the ACP was remarkable only when the poling cycle number (NL) was kept low. When ACP was continued after the saturation, dielectric and piezoelectric properties gradually dropped down to traditional direct current poled levels or even lower. Such a decrease in material properties caused by the large NL during ACP was defined as the “overpoling effect of ACP” in this study. The following lattice symmetry and domain structure characterization studies were performed through x-ray diffraction (XRD) and piezoelectric force microscopy (PFM) to find the origin of the overpoling effect. The XRD measurements combined with temperature dependence of dielectric properties demonstrated that the field-induced phase transition continued when the samples became overpoled. Further PFM measurements illustrated that the domain density of the overpoled ACP sample was significantly lower than that of the normal one, while the “2R” domain configuration was maintained through the ACP process. In addition, the hysteresis loop characterization indicated large decreases in the coercive fields. The discovered overpoling effect of ACP could help us understand the mechanisms of ACP and optimize the ACP process.}, number={19}, journal={APPLIED PHYSICS LETTERS}, author={Wan, Haotian and Luo, Chengtao and Kim, Hwang-Pill and Chung, Ching-Chang and Chang, Wei-Yi and Yamashita, Yohachi and Jiang, Xiaoning}, year={2022}, month={May} }
 @article{wan_luo_chung_yamashita_jiang_2021, title={Enhanced dielectric and piezoelectric properties of manganese-doped Pb(In1/2Nb1/2)O-3-Pb(Mg1/3Nb2/3)O-3-PbTiO3 single crystals by alternating current poling}, volume={118}, ISSN={["1077-3118"]}, DOI={10.1063/5.0038207}, abstractNote={Alternating current poling (ACP) was performed on Gen III relaxor-PT Mn-doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (Mn: PIN-PMN-PT) single crystals with the poling direction of [001]. Experimental results proved that ACP could bring property enhancement to both k31 and k33 mode crystals. Compared to those from traditional direct current poling (DCP), ACP with the optimized conditions (20 kV/cm, 0.1 Hz, and 20 cycles) enhanced the dielectric and piezoelectric properties of k31-mode mode crystals by more than 30%, where the enhanced free dielectric constant and piezoelectric coefficient d33 reached 5300 and 1750 pC/N, respectively. Furthermore, replacing DCP with ACP could increase the advantages of Gen III relaxor-PT. The coupling factors k31 and k33 were enhanced to 0.472 and 0.915, the mechanical quality factor Qm was enhanced by 17%, and the depoling temperature was raised by 17 °C to 123 °C. In the following mechanism study, in situ x-ray diffraction (XRD) combined with the temperature-dependent dielectric constant measurement proved the introduction of the monoclinic phases after ACP, while piezoresponse force microscopy (PFM) observation showed “2R”-like “2M” domain morphologies in ACP single crystals. Both these intrinsic and extrinsic factors are believed to be the keys to the mechanisms of property enhancement behind ACP. This study proved that ACP is an effective property enhancement method suitable for Gen III relaxor-PT single crystals and will promote its applications in high-temperature and high-power devices.}, number={10}, journal={APPLIED PHYSICS LETTERS}, author={Wan, Haotian and Luo, Chengtao and Chung, Ching-Chang and Yamashita, Yohachi and Jiang, Xiaoning}, year={2021}, month={Mar} }
 @article{zhang_cao_huang_danilov_chung_sun_yang_2021, title={Gamma-Ray Detection Using Bi-Poor Cs2AgBiBr6 Double Perovskite Single Crystals}, volume={9}, ISSN={["2195-1071"]}, url={https://doi.org/10.1002/adom.202001575}, DOI={10.1002/adom.202001575}, abstractNote={Abstract}, number={8}, journal={ADVANCED OPTICAL MATERIALS}, publisher={Wiley}, author={Zhang, Zheng and Cao, Da and Huang, Zhengjie and Danilov, Evgeny O. and Chung, Ching-Chang and Sun, Dali and Yang, Ge}, year={2021}, month={Apr} }
 @article{shekhawat_walters_chung_garcia_liu_jones_nishida_moghaddam_2020, title={Effect of Forming Gas Furnace Annealing on the Ferroelectricity and Wake-Up Effect of Hf0.5Zr0.5O2 Thin Films}, volume={9}, ISSN={["2162-8777"]}, DOI={10.1149/2162-8777/ab6b13}, abstractNote={The effect of furnace annealing on the ferroelectricity, leakage current, and wake-up effect in Hf0.5Zr0.5O2 (HZO) ultrathin film is studied as a function of furnace annealing temperature and gas environment after crystallizing the films with rapid thermal annealing in the presence of a TiN capping electrode. HZO films are deposited using atomic layer deposition in a Ge-HZO-TiN stack with Pt as the top contact electrode. The increment in the remanent polarization (Pr) is higher when the films are furnace annealed in the forming gas ambient. Forming gas furnace annealed films show an order of magnitude less leakage current as compared to the nitrogen annealed films. Dynamic hysteresis current measurements of the HZO ultrathin films show a faster merging of the four switching peaks after cycling the virgin forming gas furnace annealed films. H-incorporation during forming gas furnace annealing does not degrade the ferroelectric properties of HZO ultrathin films unlike conventional ferroelectrics, such as PZT or SBT. Higher Pr, lower leakage current, and an improved wake-up effect of the HZO ultrathin films show its resistance to degradation by forming gas furnace annealing, which makes ferroelectric HfO2 an ideal material for next-generation ferroelectric memory devices.}, number={2}, journal={ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY}, author={Shekhawat, Aniruddh and Walters, Glen and Chung, Ching-Chang and Garcia, Roberto and Liu, Yang and Jones, Jacob and Nishida, Toshikazu and Moghaddam, Saeed}, year={2020}, month={Jan} }
 @article{fancher_choe_gorfman_simons_chung_ziolkowski_prasertpalichat_cann_jones_2020, title={Effect of alloying BaTiO3 with BiZn1/2Ti1/2O3 on polarization reversal}, volume={117}, ISSN={["1077-3118"]}, DOI={10.1063/5.0013410}, abstractNote={Changes in the polarization state of ferroelectric materials are mediated through the motion of planar defects such as domain walls. The interplay between the two processes that enable the inversion of the macroscopic polarization in ferroelectric materials, non-180° (domain reorientation) and 180° (domain reversal), is not well understood. In this work, time-resolved x-ray diffraction was carried out during the application of an external electric field to investigate the dynamic electric-field response mechanisms of BaTiO3 (BT) and BiZn1/2Ti1/2O3(BZT)-modified BT (0.94BT-0.06BZT). These data evidence that the incorporation of BZT into BT fundamentally alters what processes are activated to reorient the polarization by 180°. Polarization reversal in BT is achieved through direct inversion of spontaneous dipoles. However, the addition of BZT into BT promotes a two-step polarization reversal process (i.e., two consecutive non-180° reorientation events).}, number={4}, journal={APPLIED PHYSICS LETTERS}, author={Fancher, C. M. and Choe, H. and Gorfman, S. and Simons, H. and Chung, C. C. and Ziolkowski, M. and Prasertpalichat, S. and Cann, D. P. and Jones, J. L.}, year={2020}, month={Jul} }
 @article{hany_yang_chung_2020, title={Fast X-ray detectors based on bulk beta-Ga2O3 (Fe)}, volume={55}, ISSN={["1573-4803"]}, url={https://doi.org/10.1007/s10853-020-04665-9}, DOI={10.1007/s10853-020-04665-9}, number={22}, journal={JOURNAL OF MATERIALS SCIENCE}, publisher={Springer Science and Business Media LLC}, author={Hany, Ibrahim and Yang, Ge and Chung, Ching-Chang}, year={2020}, month={Aug}, pages={9461–9469} }
 @article{hao_gao_neal_dudek_li_chung_guan_liu_liu_li_2020, title={Sodium tungstate-promoted CaMnO3 as an effective, phase-transition redox catalyst for redox oxidative cracking of cyclohexane}, volume={385}, ISSN={["1090-2694"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85082646635&partnerID=MN8TOARS}, DOI={10.1016/j.jcat.2020.03.022}, abstractNote={Oxidative cracking, which combines catalytic oxidation and cracking reactions, represents a promising approach to reduce the energy and carbon intensities for light olefin production from naphtha. The need to co-feed gaseous oxygen with hydrocarbons, however, leads to significant COx formation and safety concerns. The cost and energy consumption associated with air separation also affects its economic attractiveness. In this study, we investigated a redox oxidative cracking (ROC) scheme and evaluated perovskites (La0.8Sr0.2FeO3 and CaMnO3) and Na2WO4-promoted perovskite (La0.8Sr0.2FeO3@Na2WO4 and CaMnO3@Na2WO4) as the redox catalysts for ROC. CaMnO3@Na2WO4 redox catalyst shows high activity, selectivity, and stability for light olefin production from cyclohexane. Operated under a redox oxidative cracking (ROC) scheme, CaMnO3@Na2WO4 enhances the catalytic cracking of cyclohexane, while showing high selectivity towards hydrogen combustion with its built-in, active lattice oxygen. Over three-fold increase in olefin yield compared to thermal cracking and 35% yield increase compared to conventional O2-cofeed oxidative cracking were achieved. Low energy ion scattering (LEIS), X-ray photoelectric spectroscopy (XPS), and differential scanning calorimetry (DSC) indicated a core-shell structure, where a molten Na2WO4 layer covers the CaMnO3 core. Na2WO4 modifies the oxygen donation behavior of CaMnO3 and provides a catalytically active surface for cyclohexane activation. In-situ XRD revealed that CaMnO3@Na2WO4 exhibited excellent structural stability and regenerability. The transformation of Mn4+ ↔ Mn3+ ↔ Mn2+ in CaMnO3, facilitated by reversible phase transition to (Ca/Mn)O solid solution, is responsible for the lattice oxygen donation and uptake during redox cycles. Electrochemical impedance spectroscopy (EIS) measurements further confirmed that the oxygen species were transported through the molten Na2WO4 layer to participate in ROC. These findings offer mechanistic insights to design effective redox catalysts for hydrocarbon valorization using the chemical looping strategy.}, journal={JOURNAL OF CATALYSIS}, author={Hao, Fang and Gao, Yunfei and Neal, Luke and Dudek, Ryan B. and Li, Wenyuan and Chung, Chingchang and Guan, Bo and Liu, Pingle and Liu, Xingbo and Li, Fanxing}, year={2020}, month={May}, pages={213–223} }
 @article{prah_dragomir_rojac_bencan_broughton_chung_jones_sherbondy_brennecka_ursic_2020, title={Strengthened relaxor behavior in (1-x)Pb(Fe0.5Nb0.5)O-3-xBiFeO(3)}, volume={8}, ISSN={["2050-7534"]}, DOI={10.1039/c9tc05883d}, abstractNote={A systematic study of (1−x)Pb(Fe0.5Nb0.5)O3–xBiFeO3 (x = 0–0.5) was performed in order to investigate the strengthening of the relaxor properties when adding BiFeO3 into Pb(Fe0.5Nb0.5)O3 and forming a solid solution.}, number={10}, journal={JOURNAL OF MATERIALS CHEMISTRY C}, author={Prah, Uros and Dragomir, Mirela and Rojac, Tadej and Bencan, Andreja and Broughton, Rachel and Chung, Ching-Chang and Jones, Jacob L. and Sherbondy, Rachel and Brennecka, Geoff and Ursic, Hana}, year={2020}, month={Mar}, pages={3452–3462} }
 @article{zhang_chung_huang_vetter_seyitliyev_sun_gundogdu_castellano_danilov_yang_2020, title={Towards radiation detection using Cs2AgBiBr6 double perovskite single crystals}, volume={269}, ISSN={0167-577X}, url={http://dx.doi.org/10.1016/j.matlet.2020.127667}, DOI={10.1016/j.matlet.2020.127667}, abstractNote={In this work, we studied the optical- and electrical- properties of emerging Cs2AgBiBr6 double perovskite single crystals and demonstrated their potential for detecting ionizing radiation. We prepared Cs2AgBiBr6 double perovskite single crystals from a saturated aqueous solution. Low-temperature photoluminescence (PL) was employed to determine the bandgap energies of Cs2AgBiBr6, which are 2.00 eV (indirect) and 2.26 eV (direct) respectively. Using the space charge limited current method, we estimated the density of trap states and mobility of charge carriers as 1.44 × 1010 cm−3 and 7.02 cm2/V-s respectively. A lower bound value of the mobility-lifetime (μ-τ) product of 2.48 × 10−3 cm2/V was determined using 450 nm laser excitation, which was sufficient for ensuring a long drift distance of charge carriers for several radiation detector applications. Furthermore, we tested the direct response of Cs2AgBiBr6 single crystals to X-ray radiation. Our Cs2AgBiBr6 single crystal device with gold electrodes deposited on the two parallel surfaces exhibited excellent linear response to low energy X-rays.}, journal={Materials Letters}, publisher={Elsevier BV}, author={Zhang, Zheng and Chung, Ching-Chang and Huang, Zhengjie and Vetter, Eric and Seyitliyev, Dovletgeldi and Sun, Dali and Gundogdu, Kenan and Castellano, Felix N. and Danilov, Evgeny O. and Yang, Ge}, year={2020}, month={Jun}, pages={127667} }
 @article{jia_ajayi_roberts_chung_xu_2020, title={Ultrahigh-Temperature Ceramic-Polymer-Derived SiOC Ceramic Composites for High-Performance Electromagnetic Interference Shielding}, volume={12}, ISSN={["1944-8252"]}, DOI={10.1021/acsami.0c08479}, abstractNote={High-performance electromagnetic interference (EMI) shielding materials for high-temperature harsh environment are highly required for electronics and aerospace applications. Here, a composite made of ultra-high temperature ceramic and polymer derived SiOC ceramic (PDC-SiOC) with high EMI shielding was reported for such applications. A total EMI shielding efficiency (SET) of 26.67 dB with a thickness of 0.6 mm at Ka-band (26.5-40 GHz) was reported for ZrB2 fabricated by spark plasma sintering, which showed reflection dominant shielding. A unique interface of t-ZrO2 was formed after the introduction of PDC-SiOC into ZrB2. This interface has better electrical conductivity than SiOC. The composites also displayed reflection dominant shielding. Accordingly, the composite with a normalized ZrB2 fraction of 50 % pyrolyzed at 1000 °C exhibited significantly SET of 72 dB (over 99.99999 % shielded) with a thickness of 3 mm at the entire Ka-band. A maximum SET of 90.8 dB (over 99.9999999 % shielded) was achieved with a thickness of 3 mm at around 39.7 GHz.}, number={41}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Jia, Yujun and Ajayi, Tosin D. and Roberts, Mark A., Jr. and Chung, Ching-Chang and Xu, Chengying}, year={2020}, month={Oct}, pages={46254–46266} }
 @article{cho_uddin_chung_podowitz-thomas_jones_2020, title={Understanding the lithium deficient LixNiyMnzCo1-y-zO2 (x < 1) cathode materials structure (vol 228, pg 32, 2019)}, volume={242}, ISSN={["1879-3312"]}, DOI={10.1016/j.matchemphys.2019.122413}, journal={MATERIALS CHEMISTRY AND PHYSICS}, author={Cho, Sung-Jin and Uddin, Md-Jamal and Chung, Ching-Chang and Podowitz-Thomas, Stephen and Jones, Jacob L.}, year={2020}, month={Feb} }
 @article{matavz_bencan_kovac_chung_jones_trolier-mckinstry_malic_bobnar_2019, title={Additive Manufacturing of Ferroelectric-Oxide Thin-Film Multilayer Devices}, volume={11}, ISSN={["1944-8252"]}, DOI={10.1021/acsami.9b17912}, abstractNote={Additive manufacturing has dramatically transformed the design and fabrication of advanced objects. Recent advances in printing technology have led to several innovative applications; however, layer-on-layer deposition persists as a challenging issue. Here the additive manufacturing of functional-oxide devices by inkjet printing is presented. Two conditions appear critical for successful layer-on-layer printing: (i) preservation of stable surface properties, and (ii) suppression of the material accumulation at the edges of a feature upon drying. The former condition was satisfied by introducing a surface-modification layer of a polymer with a nano-textured topography, and the latter by designing the solvent composition of the ink. The developed process is highly efficient and enables conformal stacking of functional-oxide layers according to the user-defined geometry, sequence arrangement and layer thickness. To prove the effectiveness of this concept, an additive manufacture of all-oxide ferroelectric multilayer capacitors/transducers was demonstrated. Printed multi-layer devices offer a significant increase in the capacitance density and the electromechanical voltage response in comparison to the single-layer devices. Further growth in the number of available functional-oxide inks will enable arbitrary device architectures with novel functionalities.}, number={48}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Matavz, Aleksander and Bencan, Andreja and Kovac, Janez and Chung, Ching-Chang and Jones, Jacob L. and Trolier-McKinstry, Susan and Malic, Barbara and Bobnar, Vid}, year={2019}, month={Dec}, pages={45155–45160} }
 @article{zheng_lail_zhou_chun_2019, title={CaCoxZr1-xO3-delta Perovskites as Oxygen-Selective Sorbents for Air Separation}, volume={12}, ISSN={["1864-564X"]}, DOI={10.1002/cssc.201900644}, abstractNote={Abstract}, number={12}, journal={CHEMSUSCHEM}, author={Zheng, Qinghe and Lail, Marty and Zhou, Shaojun and Chun, Ching-Chang}, year={2019}, month={Jun}, pages={2598–2604} }
 @article{khazaee_sardashti_chung_sun_zhou_bergmann_dunlap-shohl_han_hill_jones_et al._2019, title={Dual-source evaporation of silver bismuth iodide films for planar junction solar cells}, volume={7}, ISSN={2050-7488 2050-7496}, url={http://dx.doi.org/10.1039/C8TA08679F}, DOI={10.1039/c8ta08679f}, abstractNote={Dual-source evaporation approach is applied to deposit AgBi2I7, AgBiI4 and Ag2BiI5 films; a planar junction AgBiI4-solar cell is demonstrated.}, number={5}, journal={Journal of Materials Chemistry A}, publisher={Royal Society of Chemistry (RSC)}, author={Khazaee, Maryam and Sardashti, Kasra and Chung, Ching-Chang and Sun, Jon-Paul and Zhou, Hanhan and Bergmann, Eric and Dunlap-Shohl, Wiley A. and Han, Qiwei and Hill, Ian G. and Jones, Jacob L. and et al.}, year={2019}, pages={2095–2105} }
 @article{shekhawat_walters_chung_garcia_liu_jones_nishida_moghaddam_2019, title={Effect of furnace annealing on the ferroelectricity of Hf0.5 Zr0.5O2 thin films}, volume={677}, ISSN={["0040-6090"]}, DOI={10.1016/j.tsf.2019.03.031}, abstractNote={The effect of furnace annealing on the ferroelectricity and crystal phase of Hf0.5ZrO2 (HZO) ultrathin films is studied as a function of film thickness. HZO films are deposited using atomic layer deposition (ALD) in a Ge-HZO-TiN stack with Pt as the top contact electrode. Furnace annealing is carried out after crystallizing the films with rapid thermal annealing in the presence of a TiN capping electrode. While furnace annealing did not have much impact on the 108 ALD cycles (~11 nm) film, it enhanced the ferroelectricity of the 44 ALD cycles film (~4.5 nm). Positive-up-negative-down tests provide evidence of ferroelectricity in the 40 ALD cycles (~4 nm) furnace annealed film after cycling the film at higher fields. Grazing incidence X-ray diffraction shows that the non-centrosymmetric orthorhombic phase responsible for ferroelectricity increased after furnace annealing in thinner films, but little change occurred in the 108 ALD cycles film that was rich in orthorhombic phase prior to furnace annealing. An analysis of the HZO films with a tapping mode atomic force microscope shows grain growth in the 44, and 40 ALD cycles films after furnace annealing.}, journal={THIN SOLID FILMS}, author={Shekhawat, Aniruddh and Walters, Glen and Chung, Ching-Chang and Garcia, Roberto and Liu, Yang and Jones, Jacob and Nishida, Toshikazu and Moghaddam, Saeed}, year={2019}, month={May}, pages={142–149} }
 @article{bradesko_fulanovic_vrabelj_otonicar_ursic_henriques_chung_jones_malic_kutnjak_et al._2019, title={Electrocaloric fatigue of lead magnesium niobate mediated by an electric-field-induced phase transformation}, volume={169}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2019.03.017}, abstractNote={Electrocaloric fatigue, i.e., the degradation of the electrocaloric temperature change of an active material under continuous electric-field cycling, has not been addressed in detail so far, despite the elevated electric fields expected for EC cooling devices. Here, we investigate the electrocaloric fatigue mechanism of a prototype relaxor material, i.e., Pb(Mg1/3Nb2/3)O3, by directly measuring its temperature response under device-relevant electric-field conditions. We show that after a critical number of field cycles the temperature of the sample begins to increase dramatically, leading to a significant degradation of the cooling properties. The degradation of cooling properties is investigated using a combination of multiscale characterization techniques, revealing that the origin of the degradation is the increased grain boundary conductance caused by an unexpected electric-field-induced phase transformation to a ferroelectric phase. We further show that this transformation and thus the fatigue can be regulated by careful control of the temperature and electric-field conditions. By revealing a previously unexplored fatigue mechanism, this study provides the first guidelines for the integration of high-performance relaxors into cooling devices.}, journal={ACTA MATERIALIA}, author={Bradesko, Andraz and Fulanovic, Lovro and Vrabelj, Marko and Otonicar, Mojca and Ursic, Hana and Henriques, Alexandra and Chung, Ching-Chang and Jones, Jacob L. and Malic, Barbara and Kutnjak, Zdravko and et al.}, year={2019}, month={May}, pages={275–283} }
 @article{jakubczyk_mapp_chung_sansom_jones_dorey_2019, title={Enhancing thermoelectric properties of NaCo2O4 ceramics through Na pre-treatment induced nano-decoration}, volume={788}, ISSN={["1873-4669"]}, DOI={10.1016/j.jallcom.2019.02.199}, abstractNote={High quality NaCo2O4 thermoelectrics are challenging to process due to the volatile nature of Na, the slow densification kinetics, and degradation of NaCo2O4 above 900–950 °C leading to the formation of Na-poor second phases. Fine grained sol-gel derived powders have been used to enhance the densification kinetics while pre-treatment of the NaCo2O4 powder with NaOH, to provide a Na rich environment, has been shown to mitigate Na loss at elevated temperatures. While insufficient to compensate for Na loss at processing temperatures of 1000 °C and above, at lower temperatures it is able to enhance densification and facilitate the formation of complex crystal structures yielding low thermal conductivity (0.66 Wm−1K−1) coupled with high electrical conductivity (3.8 × 103 Sm−1) and a Seebeck coefficient of 34.9. The resultant room temperature power factor and ZT were 6.19 × 10−6 Wm−1K−2 and 0.0026, respectively.}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, author={Jakubczyk, E. M. and Mapp, A. and Chung, C. C. and Sansom, C. L. and Jones, J. L. and Dorey, R. A.}, year={2019}, month={Jun}, pages={91–101} }
 @article{zhang_yang_zhou_chung_hany_2019, title={Optical and electrical properties of all-inorganic Cs2AgBiBr6 double perovskite single crystals}, volume={9}, ISSN={["2046-2069"]}, url={https://doi.org/10.1039/C9RA04045E}, DOI={10.1039/c9ra04045e}, abstractNote={Temperature-dependent resistivity and cathodoluminescence (CL) measurements of solution-processed Cs2AgBiBr6 double perovskite single crystals.}, number={41}, journal={RSC ADVANCES}, publisher={Royal Society of Chemistry (RSC)}, author={Zhang, Zheng and Yang, Ge and Zhou, Chuanzhen and Chung, Ching-Chang and Hany, Ibrahim}, year={2019}, month={Aug}, pages={23459–23464} }
 @article{mittmann_materano_lomenzo_park_stolichnov_cavalieri_zhou_chung_jones_szyjka_et al._2019, title={Origin of Ferroelectric Phase in Undoped HfO2 Films Deposited by Sputtering}, volume={6}, ISSN={2196-7350 2196-7350}, url={http://dx.doi.org/10.1002/ADMI.201900042}, DOI={10.1002/admi.201900042}, abstractNote={Abstract}, number={11}, journal={Advanced Materials Interfaces}, publisher={Wiley}, author={Mittmann, Terence and Materano, Monica and Lomenzo, Patrick D. and Park, Min Hyuk and Stolichnov, Igor and Cavalieri, Matteo and Zhou, Chuanzhen and Chung, Ching‐Chang and Jones, Jacob L. and Szyjka, Thomas and et al.}, year={2019}, month={Jun}, pages={1900042} }
 @article{cho_chung_podowitz-thomas_jones_2019, title={Understanding the lithium deficient LixNiyMnzCo1-y-zO2 (x < 1) cathode materials structure}, volume={228}, ISSN={["1879-3312"]}, DOI={10.1016/j.matchemphys.2019.02.028}, abstractNote={Recent works on lithium deficient LixNi1/3Mn1/3Co1/3O2 (x < 1) (NMC) cathode material has shown promises as a high voltage and high-temperature cathode material. In this work, the structure of such materials was studied with in situ XRD, DSC, and Raman spectroscopy. Moreover, to extend the understanding to higher nickel cathodes, LixNi0.6Mn0.2Co0.2O2 (x < 1) and LixNi0.8Mn0.1Co0.1O2 (x < 1) were studied together with the LixNi1/3Mn1/3Co1/3O2 (x < 1). In situ XRD results showed the lithium deficient cathode materials to be in rhombohedral (R-3m) phase at above 840 °C. A higher cation mixing is observed with increasing nickel content in the NMC cathode materials. Raman spectroscopy has indicated that MnO bonding spinel phase peak detected around 630 cm−1 and found much higher intensity for NMC111 compared to the NMC622 and NMC811. It concludes that the formation of trace spinel phase in lithium deficient NMC materials is not due to cation mixing which mostly discussed in such a high nickel content cathode materials.}, journal={MATERIALS CHEMISTRY AND PHYSICS}, author={Cho, Sung-Jin and Chung, Ching-Chang and Podowitz-Thomas, Stephen and Jones, Jacob L.}, year={2019}, month={Apr}, pages={32–36} }
 @article{baure_zhou_chung_buck_stozhkova_jones_nino_2018, title={Comparison of the in- and across-plane ionic conductivity of highly oriented neodymium doped ceria thin films}, volume={147}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2017.12.057}, abstractNote={To determine the effect of grain boundaries and grain orientation on the electrical properties of solid oxide fuel cell electrolytes, a comparison of the in-plane and across-plane ionic conductivity of both strongly and poorly textured, columnar-grained doped ceria thin films was performed within equivalent temperature ranges (150–300 °C). Additionally, the in-plane conductivity of partially amorphous films, polycrystalline films with randomly oriented grains, and single crystal, epitaxial films with no grain boundaries was determined. Pulsed laser deposition permitted the growth of all these types of films and the ability to grow columnar-grained doped ceria on both conducting and insulating surfaces enabled testing of the films both in-plane and across-plane. Compared to the columnar-grained samples, partially amorphous films exhibited a lower conductivity, while epitaxial doped ceria exhibited an enhancement in conductivity of 2 orders of magnitude. Between 300 and 400 °C, the in-plane conductivity of the strongly textured film was higher than the poorly textured one. The conductivity and activation energy in-plane and across-plane for the strongly textured film was similar (2.75 × 10−5 S/cm, 0.70 eV vs. 5.50 × 10−5 S/cm, 0.68 eV at 250 °C). In contrast, for the poorly textured films, the in-plane and across-plane conductivity values differed by almost an order of magnitude (2.86 × 10−5 S/cm, 0.55 eV vs. 1.99 × 10−4 S/cm, 0.78 eV at 250 °C) suggesting that the boundaries between oriented grains were less resistive. These results further strengthen the argument that grain orientation affects ionic transport through grain boundaries.}, journal={ACTA MATERIALIA}, author={Baure, George and Zhou, Hanhan and Chung, Ching-Chang and Buck, Marissa N. and Stozhkova, Mariia A. and Jones, Jacob L. and Nino, Juan C.}, year={2018}, month={Apr}, pages={10–15} }
 @article{zhao_hou_chung_zhou_kynast_hennig_liu_li_jones_2018, title={Deconvolved intrinsic and extrinsic contributions to electrostrain in high performance, Nb-doped Pb(ZrxTi1-x)O-3 piezoceramics (0.50 <= x <= 0.56)}, volume={158}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2018.08.006}, abstractNote={Lead zirconate titanate (PZT) is the base compound for the highest performing piezoelectric compositions. When doped with Nb, PZT has superior electrostrain and piezoelectric properties. However, the origin of that electrostrain involves both intrinsic and extrinsic contributions which have been challenging to deconvolute. In the present work, we utilize high-energy, synchrotron X-ray diffraction (XRD) in combination with an area detector to measure the response of 1% Nb-doped PbZrxTi1-xO3 (PZT, 0.50 ≤ x ≤ 0.56) piezoceramics to electric fields. Using analysis involving micromechanics-based calculations and pair distribution functions (PDFs), it is found that both the intrinsic and extrinsic contributions are important for realization of high electrostrain. In the compositions nearest the morphotropic phase boundary (MPB), the relative contributions of the intrinsic response increase. The interdependence of crystal symmetry (tetragonal and rhombohedral), spontaneous strain, and the extent of non-180° domain switching are also elucidated. An orientation dependence in the field-induced lattice strain is observed and attributed to extrinsic effects, i.e., the intergranular interaction between domain switching and lattice strain. Finally, the PDFs suggest that a continuous rotation of the polarization vector occurs in the tetragonal phase samples due to piezoelectric distortion, being most obvious in the compositions near the MPB, but is not observed in the rhombohedral phase samples.}, journal={ACTA MATERIALIA}, author={Zhao, Changhao and Hou, Dong and Chung, Ching-Chang and Zhou, Hanhan and Kynast, Antje and Hennig, Eberhard and Liu, Wenfeng and Li, Shengtao and Jones, Jacob L.}, year={2018}, month={Oct}, pages={369–380} }
 @article{chang_chung_luo_kim_yamashita_jones_jiang_2018, title={Dielectric and piezoelectric properties of 0.7 Pb(Mg1/3Nb2/3)O-3-0.3 PbTiO3 single crystal poled using alternating current}, volume={6}, ISSN={["2166-3831"]}, DOI={10.1080/21663831.2018.1498812}, abstractNote={ABSTRACT In this paper, 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-30%PT) single crystal samples were poled using an alternating current (electric field) poling (ACP) method. Compared to the traditional poling method, the piezoelectric coefficient, free and clamped dielectric constants were improved more than 21%. X-ray diffraction result suggests the existence of monoclinic phase (MA) in ACP samples and piezoresponse force microscopy (PFM) result further depicts the finer engineered domain structures. The ACP sample also showed the unique phase transition sequences during the depoling process. Our work could provide a novel domain engineered method to enhance piezoelectric properties of PMN-PT single crystal. GRAPHICAL ABSTRACT IMPACT STATEMENT Piezoelectric and dielectric properties of relaxor-PT single crystals can be significantly enhanced by employing the new alternating current poling method, attributing to the unique heterogenous domain structure containing unprecedented domain wall density.}, number={10}, journal={MATERIALS RESEARCH LETTERS}, author={Chang, Wei-Yi and Chung, Ching-Chang and Luo, Chengtao and Kim, Taeyang and Yamashita, Yohachi and Jones, Jacob L. and Jiang, Xiaoning}, year={2018}, pages={537–544} }
 @article{park_chung_schenk_richter_opsomer_detavernier_adelmann_jones_mikolajick_schroeder_2018, title={Effect of annealing ferroelectric HfO2 thin films: in situ, high temperature x-ray diffraction}, volume={4}, number={7}, journal={Advanced Electronic Materials}, author={Park, M. H. and Chung, C. C. and Schenk, T. and Richter, C. and Opsomer, K. and Detavernier, C. and Adelmann, C. and Jones, J. L. and Mikolajick, T. and Schroeder, U.}, year={2018} }
 @article{ciuchi_chung_fancher_capiani_jones_mitoseriu_galassi_2018, title={Field induced metastable ferroelectric phase in Pb0.97La0.03(Zr0.90Ti0.10)(Zr0.90Ti0.10)(0.9925)O-3 ceramics}, volume={38}, ISSN={["1873-619X"]}, DOI={10.1016/j.jeurceramsoc.2017.11.009}, abstractNote={Pb0.97La0.03(Zr0.9Ti0.1)0.9925O3 (PLZT 3/90/10) ceramics prepared by solid-state reaction with the compositions near the antiferroelectric/ferroelectric (FE/AFE) phase boundary were studied. From the polarization–electric field P(E) dependence and ex situ X-ray study, an irreversible electric field induced AFE-to-FE phase transition is verified at room temperature. Dielectric and in situ temperature dependent X-ray analysis evidence that the phase transition sequence in PLZT 3/90/10-based ceramics can be readily altered by poling. A first order antiferroelectric-paraelectric (AFE-to-PE) transition occurred at ∼190 °C in virgin sample and at ∼180 °C in poled sample. In addition, a FE-to-AFE transition occurs in the poled ceramic at much lower temperatures (∼120 °C) with respect to the Curie range (∼190 °C). The temperature-induced FE-to-AFE transition is diffuse and takes place in a broad temperature range of 72–135 °C. The recovery of AFE is accompanied by an enhancement in the piezoelectric properties.}, number={4}, journal={JOURNAL OF THE EUROPEAN CERAMIC SOCIETY}, author={Ciuchi, I. V. and Chung, C. C. and Fancher, C. M. and Capiani, C. and Jones, J. L. and Mitoseriu, L. and Galassi, C.}, year={2018}, month={Apr}, pages={1479–1487} }
 @article{yoo_chung_kelley_park_2018, title={Graphitization Behavior of Loblolly Pine Wood Investigated by in Situ High Temperature X-ray Diffraction}, volume={6}, ISSN={["2168-0485"]}, DOI={10.1021/acssuschemeng.8b01446}, abstractNote={Graphitization is a complex process involving chemical and morphological changes, although the detailed mechanism for different starting materials is not well understood. In this work, in situ high temperature X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were used to examine the phase transition occurring between 1000 and 1500 °C in loblolly pine wood-derived carbon materials. Electron energy loss spectroscopy (EELS) was also used to study these wood-derived carbon materials. XRD data showed the disappearance of a disordered carbon phase between 1300 and 1400 °C, followed by the formation of a crystalline graphitic phase between 1400 and 1500 °C. Lattice parameters and the crystal structure of the loblolly pine wood-derived graphite were systematically calculated from the empirical data. The presence of a large endothermic peak at 1500 °C in the DSC thermogram supported this observation. Selected area electron diffraction patterns showed the growth of graphitic crystallites after he...}, number={7}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Yoo, Seunghyun and Chung, Ching-Chang and Kelley, Stephen S. and Park, Sunkyu}, year={2018}, month={Jul}, pages={9113–9119} }
 @article{schroeder_richter_park_schenk_pesic_hoffmann_fengler_pohl_rellinghaus_zhou_et al._2018, title={Lanthanum-Doped Hafnium Oxide: A Robust Ferroelectric Material}, volume={57}, ISSN={["1520-510X"]}, DOI={10.1021/acs.inorgchem.7b03149}, abstractNote={Recently simulation groups have reported the lanthanide series elements as the dopants that have the strongest effect on the stabilization of the ferroelectric non-centrosymmetric orthorhombic phase in hafnium oxide. This finding confirms experimental results for lanthanum and gadolinium showing the highest remanent polarization values of all hafnia-based ferroelectric films until now. However, no comprehensive overview that links structural properties to the electrical performance of the films in detail is available for lanthanide-doped hafnia. La:HfO2 appears to be a material with a broad window of process parameters, and accordingly, by optimization of the La content in the layer, it is possible to improve the performance of the material significantly. Variations of the La concentration leads to changes in the crystallographic structure in the bulk of the films and at the interfaces to the electrode materials, which impacts the spontaneous polarization, internal bias fields, and with this the field cycling behavior of the capacitor structure. Characterization results are compared to other dopants like Si, Al, and Gd to validate the advantages of the material in applications such as semiconductor memory devices.}, number={5}, journal={INORGANIC CHEMISTRY}, author={Schroeder, Uwe and Richter, Claudia and Park, Min Hyuk and Schenk, Tony and Pesic, Milan and Hoffmann, Michael and Fengler, Franz P. G. and Pohl, Darius and Rellinghaus, Bernd and Zhou, Chuanzhen and et al.}, year={2018}, month={Mar}, pages={2752–2765} }
 @article{zhu_yan_dirican_zhu_zang_selvan_chung_jia_li_kiyak_et al._2018, title={Li0.33La0.557TiO3 ceramic nanofiber-enhanced polyethylene oxide-based composite polymer electrolytes for all-solid-state lithium batteries}, volume={6}, ISSN={["2050-7496"]}, url={https://publons.com/publon/1573984/}, DOI={10.1039/c7ta10517g}, abstractNote={A polyethylene oxide-based composite solid polymer electrolyte filled with one-dimensional ceramic Li0.33La0.557TiO3 nanofibers was designed and prepared.}, number={10}, journal={JOURNAL OF MATERIALS CHEMISTRY A}, publisher={Royal Society of Chemistry (RSC)}, author={Zhu, Pei and Yan, Chaoyi and Dirican, Mahmut and Zhu, Jiadeng and Zang, Jun and Selvan, R. Kalai and Chung, Ching-Chang and Jia, Hao and Li, Ya and Kiyak, Yasar and et al.}, year={2018}, month={Mar}, pages={4279–4285} }
 @article{li_shahbazi_wang_zhang_chung_dayton_yan_2018, title={Nanostructured molybdenum carbide on biochar for CO2 reforming of CH4}, volume={225}, ISSN={["1873-7153"]}, DOI={10.1016/j.fuel.2018.03.179}, abstractNote={A simple procedure was developed to synthesize molybdenum carbide nanoparticles (Mo2C/BC) by carburization of molybdate salts supported on the biochar from pyrolysis of biomass without using extra carbon source or reducing gas. The molybdenum carbide formation procedure investigated by in-situ XRD and TGA-MS indicated that the phase transitions followed the path of (NH4)6Mo7O24·4H2O → (NH4)2Mo3O10 → (NH4)2Mo14O42 → Mo8O23 → Mo4O11 → MoO2 → Mo2C. The volatile gases CO, H2, and CH4 evolved from biochar and the biochar solid carbon participated in the reduction of molybdenum species, while the biochar and CH4 served as carbon sources for the carburization. Temperature programmed surface reactions of Mo2C/BC indicated that CH4 dissociated as CH4 ⇋ C∗ + 2H2 on the catalyst surface, and CO2 reacted as CO2 + C∗ ⇋ 2CO+ ∗ due to oxidation of Mo2C. Both experiment data and thermodynamic analysis for the study of operation conditions of CO2 reforming of CH4 clearly demonstrated that the yields of H2 and CO increased with the increased temperature and the reasonable conversions should be performed at 850 °C, at which both CH4 and CO2 conversions were higher than 80%.}, journal={FUEL}, author={Li, Rui and Shahbazi, Abolghasem and Wang, Lijun and Zhang, Bo and Chung, Ching-Chang and Dayton, David and Yan, Qiangu}, year={2018}, month={Aug}, pages={403–410} }
 @article{park_chung_schenk_richter_hoffmann_wirth_jones_mikolajick_schroeder_2018, title={Origin of temperature-dependent ferroelectricity in Si-Doped HfO2}, volume={4}, number={4}, journal={Advanced Electronic Materials}, author={Park, M. H. and Chung, C. C. and Schenk, T. and Richter, C. and Hoffmann, M. and Wirth, S. and Jones, J. L. and Mikolajick, T. and Schroeder, U.}, year={2018} }
 @article{chang_chung_yuan_chang_tian_viehland_li_jones_jiang_2018, title={Patterned nano-domains in PMN-PT single crystals}, volume={143}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2017.10.016}, abstractNote={The domain structure, dielectric, and piezoelectric properties of 0.7 Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMN-PT) single crystals with nanocomposite electrode, which includes MnOx semiconductor nanogratings and a Ti/Au conductive layer, were studied in this paper. These artificial MnOx nanogratings can alter the electric field distribution and then enhance the domain density. PMN-PT crystals with Ti/Au-MnOx nanocomposite electrodes showed high piezoelectric constant of 2250 p.m./V and dielectric constant of 5400 at 1 kHz, respectively. Compared to ones with conventional planar electrodes, the piezoelectric and dielectric constants of the samples with nanocomposite electrodes were increased 36.7% and 38.3%, respectively. Piezoresponse force microscopy (PFM) images revealed the domain pattern near the electrode/single crystal interface. A linear domain structure induced by the MnOx nanocomposite electrode was found in the samples with thickness less than 200 μm. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) results showed the diffusion of Mn about 300 nm in depth in PMNPT crystal after heat treatment during MnOx nanocomposite electrode. It is believed that the localized high electric fields induced by fringe effects caused by the nanocomposite electrode can enhance nucleation of new domains, and that diffusion from the patterned Mn layer may also lead to an enhancement in domain wall mobility. Our findings open up a new domain engineering technique for tailoring the dielectric and piezoelectric properties of PMN-PT single crystals.}, journal={Acta Materialia}, author={Chang, W.-Y. and Chung, C.-C. and Yuan, Z. and Chang, C.-H. and Tian, J. and Viehland, D. and Li, J.-F. and Jones, J.L. and Jiang, X.}, year={2018}, month={Jan}, pages={166–173} }
 @article{narayanan_caydamli_tekinalp_matai_boy_chung_shen_gupta_tonelli_2018, title={Thermal, mechanical, and topographical evaluation of nonstoichiometric alpha-cyclodextrin/poly(epsilon-caprolactone) pseudorotaxane nucleated poly(epsilon-caprolactone) composite films}, volume={56}, ISSN={["1099-0488"]}, DOI={10.1002/polb.24741}, abstractNote={ABSTRACT}, number={22}, journal={JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS}, publisher={Wiley}, author={Narayanan, Ganesh and Caydamli, Yavuz and Tekinalp, Halil and Matai, Ishita and Boy, Ramiz and Chung, Ching-Chang and Shen, Jialong and Gupta, Bhupender S. and Tonelli, Alan E.}, year={2018}, month={Nov}, pages={1529–1537} }
 @article{lomenzo_chung_zhou_jones_nishida_2017, title={Doped Hf0.5Zr0.5O2 for high efficiency integrated supercapacitors}, volume={110}, number={23}, journal={Applied Physics Letters}, author={Lomenzo, P. D. and Chung, C. C. and Zhou, C. Z. and Jones, J. L. and Nishida, T.}, year={2017} }
 @article{ciuchi_chung_fancher_guerrier_forrester_jones_mitoseriu_galassi_2017, title={Field-induced antiferroelectric to ferroelectric transitions in (Pb1-xLax)(Zr0.90Ti0.10)(1-x)/O-4(3) investigated by in situ X-ray diffraction}, volume={37}, ISSN={["1873-619X"]}, DOI={10.1016/j.jeurceramsoc.2017.06.018}, abstractNote={Phase transitions and field-induced preferred orientation in (Pb1-xLax)(Zr0.90Ti0.10)1–x/4O3 (PLZT x/90/10) ceramics upon electric field cycling using in situ X-ray diffraction were studied. The evolution of the {200}pc and {111}pc diffraction line profiles indicate that PLZT 4/90/10 and PLZT 3/90/10 compositions undergo an antiferroelectric (AFE)–ferroelectric (FE) phase switching. Both PLZT 4/90/10 and PLZT 3/90/10 exhibit irreversible preferred orientation after experiencing the field-induced AFE-to-FE phase switching. An electric field-induced structure develops in both compositions which has a reversible character during the field decreasing in PLZT 4/90/10 and an irreversible character in PLZT 3/90/10. In addition, structural analysis of pre-poled PLZT 3/90/10 ceramics show that it is possible to induce consecutive FE-to-AFE and AFE-to-FE transitions when fields of reversed polarity are applied in sequence. The field range required to induce the AFE phase is broad, and the phase transition is kinetically slow. This kind of transition has rarely been reported before.}, number={15}, journal={JOURNAL OF THE EUROPEAN CERAMIC SOCIETY}, author={Ciuchi, I. V. and Chung, C. C. and Fancher, C. M. and Guerrier, J. and Forrester, J. S. and Jones, J. L. and Mitoseriu, L. and Galassi, C.}, year={2017}, month={Dec}, pages={4631–4636} }
 @article{yu_chung_shewmon_ho_carpenter_larrabee_sun_jones_ade_o'connor_et al._2017, title={Flexible inorganic ferroelectric thin films for nonvolatile memory devices}, volume={27}, number={21}, journal={Advanced Functional Materials}, author={Yu, H. and Chung, C. C. and Shewmon, N. and Ho, S. and Carpenter, J. H. and Larrabee, R. and Sun, T. L. and Jones, J. L. and Ade, H. and O'Connor, B. T. and et al.}, year={2017} }
 @article{baure_zhou_chung_stozhkova_jones_nino_2017, title={Grain orientation effects on the ionic conductivity of neodymia doped ceria thin films}, volume={133}, ISSN={["1873-2453"]}, DOI={10.1016/j.actamat.2017.05.030}, abstractNote={It is generally accepted that grain boundaries in the path of transport are detrimental to ionic conductivity. To delve deeper into the connection between grain boundaries and ionic transport, the relative orientations of the grains were determined using the transmission Kikuchi diffraction technique. Nanocrystalline (grain size ∼ 40 nm) neodymia doped ceria thin films grown via pulsed laser deposition amplify the effect of these intrinsic interfaces. In addition, this deposition technique allowed the growth of partially amorphous and columnar grained films. Further, the strength of the texture in the columnar grained films was modified by changing substrates. The in-plane impedance measurements were able to isolate the response of the film from the response of the electrode interface and confirmed the majority carriers were oxygen vacancies at low temperatures. The anionic conductivity improved as the strength of the texture in the films increased. The conductivity of the strongly textured films was 2 orders of magnitude higher than the conductivity of the randomly oriented ones between 300 and 400 °C. Also, the in-plane conductivity per grain was more than 3 orders of magnitude higher in the strongly textured film than in the poorly textured one indicating conductivity is not dependent on grain boundary density. IV measurements revealed that grain boundaries posed a potential barrier to anions in the poorly textured and randomly oriented films, but not in the strongly textured samples. The type of grain boundary was deemed a contributing factor. Boundaries between more misaligned grains were more resistive decreasing the total conductivity.}, journal={ACTA MATERIALIA}, author={Baure, George and Zhou, Hanhan and Chung, Ching-Chang and Stozhkova, Mariia A. and Jones, Jacob L. and Nino, Juan C.}, year={2017}, month={Jul}, pages={81–89} }
 @article{zhao_hou_chung_yu_liu_li_jones_2017, title={Local structural behavior of PbZr0.5Ti0.5O3 during electric field application via in situ pair distribution function study}, volume={122}, number={17}, journal={Journal of Applied Physics}, author={Zhao, C. H. and Hou, D. and Chung, C. C. and Yu, Y. Y. and Liu, W. F. and Li, S. T. and Jones, J. L.}, year={2017} }
 @article{chung_fancher_isaac_nikkel_hennig_jones_2017, title={Temperature dependence of field-responsive mechanisms in lead zirconate titanate}, volume={100}, ISSN={["1551-2916"]}, DOI={10.1111/jace.14979}, abstractNote={Abstract}, number={9}, journal={JOURNAL OF THE AMERICAN CERAMIC SOCIETY}, author={Chung, Ching-Chang and Fancher, Chris M. and Isaac, Catherine and Nikkel, Jason and Hennig, Eberhard and Jones, Jacob L.}, year={2017}, month={Sep}, pages={4352–4361} }
 @article{pan_chung_he_jones_gao_2016, title={Accelerated Thermal Decomposition of Graphene Oxide Films in Air via in Situ X-ray Diffraction Analysis}, volume={120}, ISSN={["1932-7455"]}, DOI={10.1021/acs.jpcc.6b05031}, abstractNote={Thermal decomposition of graphene oxide (GO) has been extensively investigated in the past decade, but the detailed reaction kinetics remains elusive so far. Here we employ an in situ X-ray diffraction (XRD) analysis to clarify the kinetics of GO decomposition in different atmospheres and sample morphologies. The XRD peak (002), which is the major diffraction peak corresponding to the interlayer distance in GO samples, shifted from 11.5° to 23° along with significant decrease in intensity when samples were heated from 25 to 350 °C. The decomposition in air exhibits a higher reaction rate compared with that in pure nitrogen gases because the O2 molecules in air facilitate the oxidation of carbon atoms, leading to the evolution of CO and CO2. Free-standing films of GO also decompose significantly faster than GO powders, owing to their slower heat dissipation into the environment and higher thermal conductivity within the well-stacked lamella. This study has provided new insights into the reaction kinetics o...}, number={27}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, author={Pan, Qin and Chung, Ching-Chang and He, Nanfei and Jones, Jacob L. and Gao, Wei}, year={2016}, month={Jul}, pages={14984–14990} }
 @article{narayanan_chung_aguda_boy_hartman_mehraban_gupta_tonelli_2016, title={Correlation of the stoichiometries of poly-(epsilon-caprolactone) and alpha-cyclodextrin pseudorotaxanes with their solution rheology and the molecular orientation, crystallite size, and thermomechanical properties of their nanofibers}, volume={6}, ISSN={["2046-2069"]}, DOI={10.1039/c6ra23536k}, abstractNote={Pseudorotaxane nanofibers based on biomedical polymers, such as poly(ε-caprolactone) (PCL), and α-cyclodextrins (α-CD) open new horizons for a variety of biomedical applications.}, number={112}, journal={RSC ADVANCES}, publisher={Royal Society of Chemistry (RSC)}, author={Narayanan, Ganesh and Chung, Ching-Chang and Aguda, Remil and Boy, Ramiz and Hartman, Matthew and Mehraban, Nahid and Gupta, Bhupender S. and Tonelli, Alan E.}, year={2016}, pages={111326–111336} }
 @article{zoellner_stuart_chung_dougherty_jones_maggard_2016, title={CuNb1−xTaxO3 (x ≤ 0.25) solid solutions: impact of Ta(v) substitution and Cu(i) deficiency on their structure, photocatalytic, and photoelectrochemical properties}, volume={4}, ISSN={2050-7488 2050-7496}, url={http://dx.doi.org/10.1039/c5ta06609c}, DOI={10.1039/c5ta06609c}, abstractNote={Investigation of CuNb1−xTaxO3has led to new insights into the visible-light photocurrents and photocatalytic activities of solid solutions.}, number={8}, journal={Journal of Materials Chemistry A}, publisher={Royal Society of Chemistry (RSC)}, author={Zoellner, Brandon and Stuart, Sean and Chung, Ching-Chang and Dougherty, Daniel B. and Jones, Jacob L. and Maggard, Paul A.}, year={2016}, pages={3115–3126} }
 @article{narayanan_aguda_hartman_chung_boy_gupta_tonelli_2016, title={Fabrication and Characterization of Poly(epsilon-caprolactone)/alpha-Cyclodextrin Pseudorotaxane Nanofibers}, volume={17}, ISSN={["1526-4602"]}, DOI={10.1021/acs.biomac.5b01379}, abstractNote={Multifunctional scaffolds comprising neat poly(ε-caprolactone) (PCL) and α-cyclodextrin pseudorotaxanated in α-cyclodextrin form have been fabricated using a conventional electrospinning process. Thorough in-depth characterizations were performed on the pseudorotaxane nanofibers prepared from chloroform (CFM) and CFM/dimethylformamide (DMF) utilizing scanning electron microscopy (SEM), transmission electron microscopy (TEM), rheology, differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), wide-angle X-ray diffraction (WAXD), and Instron tensile testing. The results indicate the nanofibers obtained from chloroform retain the rotaxanated structure; while those obtained from CFM/DMF had significantly dethreaded during electrospinning. As a consequence, the nanowebs obtained from CFM showed higher moduli and lower elongations at break compared to neat PCL nanowebs and PCL/α-CD nanowebs electrospun from CFM/DMF.}, number={1}, journal={BIOMACROMOLECULES}, publisher={American Chemical Society (ACS)}, author={Narayanan, Ganesh and Aguda, Remil and Hartman, Matthew and Chung, Ching-Chang and Boy, Ramiz and Gupta, Bhupender S. and Tonelli, Alan E.}, year={2016}, month={Jan}, pages={271–279} }
 @article{boy_narayanan_chung_kotek_2016, title={Novel cellulose-collagen blend biofibers prepared from an amine/salt solvent system}, volume={92}, ISSN={["1879-0003"]}, url={https://doi.org/10.1016/j.ijbiomac.2016.08.010}, DOI={10.1016/j.ijbiomac.2016.08.010}, abstractNote={Cellulose/collagen biofibers were produced from ethylene diamine/potassium thiocyanate binary solvent system, with methanol as a coagulant. The dynamic viscosity of the solutions decreased with the gradual increase in the collagen content up to 40%. The elemental analysis showed incorporation of collagen into cellulose matrix, thereby demonstrating some degree of interaction with the cellulose matrix. The chemical and thermal analysis further revealed an intermolecular interaction between cellulose and the protein and improved thermal stability, respectively. Furthermore, the electron microscopy images mostly exhibited fibrillar morphology with no visible phase separation, indicating compatibility between the two phases. Moreover, biofibers containing higher cellulose content showed higher crystallinity, tensile, and birefringence properties of the composite fibers.}, journal={INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES}, publisher={Elsevier BV}, author={Boy, Ramiz and Narayanan, Ganesh and Chung, Ching-Chang and Kotek, Richard}, year={2016}, month={Nov}, pages={1197–1204} }
 @article{lomenzo_takmeel_zhou_chung_moghaddam_jones_nishida_2015, title={Mixed Al and Si doping in ferroelectric HfO2 thin films}, volume={107}, number={24}, journal={Applied Physics Letters}, author={Lomenzo, P. D. and Takmeel, Q. and Zhou, C. Z. and Chung, C. C. and Moghaddam, S. and Jones, J. L. and Nishida, T.}, year={2015} }