@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{zheng_xiang_xu_luo_wang_liu_han_zhao_chen_chen_et al._2018, title={Controlling Surface Oxides in Si/C Nanocomposite Anodes for High-Performance Li-Ion Batteries}, volume={8}, ISSN={["1614-6840"]}, DOI={10.1002/aenm.201801718}, abstractNote={Abstract}, number={29}, journal={ADVANCED ENERGY MATERIALS}, author={Zheng, Guorui and Xiang, Yuxuan and Xu, Liangfan and Luo, Hao and Wang, Baolin and Liu, Yang and Han, Xiang and Zhao, Weimin and Chen, Shijian and Chen, Hailong and et al.}, year={2018}, month={Oct} }
 @article{deshmukh_sharma_nalamati_reynolds_liu_iyer_2018, title={Molecular beam epitaxial growth of high quality Ga-catalyzed GaAs1-xSbx(x > 0.8) nanowires on Si (111) with photoluminescence emission reaching 1.7 mu m}, volume={33}, ISSN={["1361-6641"]}, DOI={10.1088/1361-6641/aae7b8}, abstractNote={The advancement of ternary GaAsSb mismatched alloy system toward the Sb-rich corner of the phase diagram in the nanowire (NW) configuration on silicon remains a challenge. A large lattice mismatch between the silicon substrate and GaAsSb with an Sb-rich composition, along with the low supersaturation and low solubility of Sb in the Ga droplet in the vapor–liquid–solid growth mechanism, causes significant issues during Ga-assisted molecular beam epitaxial growth of these NWs. In this work, we have carried out a systematic study of Sb-rich GaAs1–xSbx NWs grown on Si (111) using variations of the Ga, As, and Sb beam equivalent pressures (BEP) to minimize undesirable parasitic growth and achieve photoemission up to 1.7 μm. Ga-assisted molecular beam epitaxy is the enabling growth technology for the growth of these self-catalyzed GaAs1–xSbx (x > 0.8) NWs. The use of a dual substrate temperature approach along with low As background pressure and a low Ga BEP were found to be the key growth components in achieving a well-faceted NW morphology with a low parasitic layer on the substrate. Energy-dispersive x-ray spectroscopy analysis confirms uniform compositional homogeneity along the NWs, while selected-area electron diffraction patterns in the transmission electron microscope revealed a zinc-blende crystal structure. A peak μ-photoluminescence emission of 1680 nm with a narrow FWHM was obtained at 4 K. Raman spectra at room temperature exhibit only GaSb related LO and TO modes, which attest to the high quality of the NWs grown. This is a promising approach due to the broad scope of applicability to grow other mismatched alloy material systems in a NW configuration.}, number={12}, journal={SEMICONDUCTOR SCIENCE AND TECHNOLOGY}, author={Deshmukh, Prithviraj and Sharma, Manish and Nalamati, Surya and Reynolds, C. Lewis, Jr. and Liu, Yang and Iyer, Shanthi}, year={2018}, month={Dec} }
 @article{zhang_zhou_gao_mankoci_liu_sang_qin_hou_ren_doll_et al._2018, title={The effects of laser shock peening on the mechanical properties and biomedical behavior of AZ31B magnesium alloy}, volume={339}, ISSN={["0257-8972"]}, DOI={10.1016/j.surfcoat.2018.02.009}, abstractNote={Mg alloys offer potential advantages over conventional biomedical implant materials because of their biodegradability and biocompatibility, but could be limited by their poor mechanical properties. In this study, laser shock peening (LSP), a surface processing technique, was applied to improve the mechanical properties of the AZ31B magnesium (Mg) alloy. It was demonstrated that LSP increased the hardness and yield strength of the Mg alloy. Due to the hardening, LSP significantly improved the wear resistance and fatigue performance of the Mg alloy. In addition, immersion tests carried out in cell culture medium revealed that LSP did not significantly increase Mg2+ release and weight loss. Furthermore, an in vitro cell culture study showed that the LSP-treated samples have cell-compatibility comparable to untreated samples. Thus, the LSP technique could, with further study, advance the clinical utility of Mg alloys in the orthopedic field.}, journal={SURFACE & COATINGS TECHNOLOGY}, author={Zhang, Ruixia and Zhou, Xianfeng and Gao, Hongyu and Mankoci, Steven and Liu, Yang and Sang, Xiahan and Qin, Haifeng and Hou, Xiaoning and Ren, Zhencheng and Doll, Gary L. and et al.}, year={2018}, month={Apr}, pages={48–56} }
 @inproceedings{liu_rollins_dinh_luo_2017, title={Sensitivity analysis of interfacial momentum closure terms in two phase flow and boiling simulations using MCFD solver}, volume={2}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85032902821&partnerID=MN8TOARS}, DOI={10.1115/ht2017-4963}, abstractNote={In this paper, a general workflow for the global Sensitivity Analysis (SA) has been proposed based on the coupling of VUQ toolkit DAKOTA and Multiphase Computational Fluid Dynamics (MCFD) solver boilEulerFoam. A surrogate model is first constructed based on sampling simulations from boilEulerFoam. This surrogate is based on Gaussian Processes Model (GPM) and is validated and proved to have good properties. The Morris Screening method is then applied based on the surrogate to those interfacial momentum closure terms for SA, including drag, lift, turbulent dispersion, wall lubrication, and virtual mass. Two different cases are considered, one is on low-pressure adiabatic flow, and the other is on high pressure boiling flow. Each case has its experimental background with data support. The radial void fraction distribution, gas velocity, relative velocity and liquid temperature (only for high pressure boiling case) are chosen as the Quantities of Interest (QoIs) which are of key interests for two-phase flow simulation and boiling crisis prediction. The interfacial force coefficient of each closure term is chosen as the input parameter. For the boiling case, the bubble diameter effect is also analyzed.}, booktitle={ASME 2017 Heat Transfer Summer Conference, HT 2017}, author={Liu, Y. and Rollins, C. and Dinh, Nam and Luo, H.}, year={2017} }
 @article{kasanaboina_ahmad_li_reynolds_liu_iyer_2015, title={Self-catalyzed growth of dilute nitride GaAs/GaAsSbN/GaAs core-shell nanowires by molecular beam epitaxy}, volume={107}, ISSN={["1077-3118"]}, DOI={10.1063/1.4930887}, abstractNote={Bandgap tuning up to 1.3 μm in GaAsSb based nanowires by incorporation of dilute amount of N is reported. Highly vertical GaAs/GaAsSbN/GaAs core-shell configured nanowires were grown for different N contents on Si (111) substrates using plasma assisted molecular beam epitaxy. X-ray diffraction analysis revealed close lattice matching of GaAsSbN with GaAs. Micro-photoluminescence (μ-PL) revealed red shift as well as broadening of the spectra attesting to N incorporation in the nanowires. Replication of the 4K PL spectra for several different single nanowires compared to the corresponding nanowire array suggests good compositional homogeneity amongst the nanowires. A large red shift of the Raman spectrum and associated symmetric line shape in these nanowires have been attributed to phonon localization at point defects. Transmission electron microscopy reveals the dominance of stacking faults and twins in these nanowires. The lower strain present in these dilute nitride nanowires, as opposed to GaAsSb nanowires having the same PL emission wavelength, and the observation of room temperature PL demonstrate the advantage of the dilute nitride system offers in the nanowire configuration, providing a pathway for realizing nanoscale optoelectronic devices in the telecommunication wavelength region.}, number={10}, journal={APPLIED PHYSICS LETTERS}, author={Kasanaboina, Pavan Kumar and Ahmad, Estiak and Li, Jia and Reynolds, C. Lewis, Jr. and Liu, Yang and Iyer, Shanthi}, year={2015}, month={Sep} }