@article{chen_white_goto_dickey_2016, title={Directionally Solidified Boride and Carbide Eutectic Ceramics}, volume={99}, ISSN={0002-7820}, url={http://dx.doi.org/10.1111/jace.14287}, DOI={10.1111/jace.14287}, abstractNote={Borides and carbides generally have outstanding hardness, excellent wear resistance, and high melting points due to their covalent bonding. Directionally solidified eutectic (DSE) composites of boride and carbide constituent phases have been investigated since the 1970s as an approach to produce dense composite microstructures with added control over the microstructure. A variety of DSE ceramic composites have been developed and evaluated as potential materials for structural and functional applications due to their unique thermo‐electro‐mechanical properties. Renewed interest over the past few decades has been motivated, in part, by the needs for ultrahigh‐temperature composites for aerospace applications along with low‐density composites for armor applications. Some directionally solidified boride and carbide DSEs exhibit advantages in material properties over monolithic materials. This study reviews historical and recent research on processing methods, microstructure, crystallography, and material properties (mechanical, electrical, thermal properties, and oxidation resistance) of directionally solidified boride and carbide eutectic ceramic composites. Opportunities along with current limitations and needs for future developments are also reviewed and discussed.}, number={6}, journal={Journal of the American Ceramic Society}, publisher={Wiley}, author={Chen, Wei-Ting and White, Ryan M. and Goto, Takashi and Dickey, Elizabeth C.}, editor={Green, D. J.Editor}, year={2016}, month={May}, pages={1837–1851} }
 @article{ojha_kasanaboina_reynolds_rawdanowicz_liu_white_iyer_2016, title={Incorporation of Be dopant in GaAs core and core-shell nanowires by molecular beam epitaxy}, volume={34}, ISSN={["2166-2746"]}, DOI={10.1116/1.4943600}, abstractNote={Effective implementation of doped nanowires (NWs) in nanoscaled devices requires controlled and effective dopant incorporation. The one dimensional configuration of NWs poses a challenge for efficient doping due to the large number of surface states pinning the Fermi level close to the middle of the band gap and thus creating a large depletion layer at the surface. This effectively reduces the effective volume for doping. However, the flexibility of different architectures offered by the NWs, in particular, the core–shell configuration along with different growth mechanisms associated with the core and shell can be strategically used for efficient doping. In this work, the authors report on a catalyst free Ga-assisted approach for the growth of Be-doped GaAs NWs by molecular beam epitaxy. A systematic and a comprehensive study is reported using a variety of characterization techniques to determine the impact of NW configuration, Be cell temperature, and V/III beam equivalent pressure (BEP) ratio individually on doping incorporation in the NWs. Broadening of the photoluminescence spectra in the 1.49–1.51 eV range, as well as the longitudinal optical mode of the corresponding Raman spectra in combination with its red shift that is considered as a signature of higher Be incorporation, was found to occur for the core–shell configuration. Further, a lower V/III BEP ratio has a strong impact on enhancing the dopant incorporation.}, number={2}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Ojha, Sai Krishna and Kasanaboina, Pavan Kumar and Reynolds, Claude Lewis, Jr. and Rawdanowicz, Thomas A. and Liu, Yang and White, Ryan M. and Iyer, Shanthi}, year={2016}, month={Mar} }
 @article{huang_zhou_tra_white_trappen_n'diaye_spencer_frye_cabrera_nguyen_et al._2015, title={Imaging magnetic and ferroelectric domains and interfacial spins in magnetoelectric La0.7Sr0.3MnO3/PbZr0.2Ti0.8O3 heterostructures}, volume={27}, ISSN={["1361-648X"]}, DOI={10.1088/0953-8984/27/50/504003}, abstractNote={Strong magnetoelectric coupling can occur at the interface between ferromagnetic and ferroelectric films. Similar to work on interfacial exchange bias, photoemission electron microscopy was utilized to image both magnetic and ferroelectric domains and the resulting interfacial Ti spin in the same locations of La0.7Sr0.3MnO3/PbZr0.2Ti0.8O3 heterostructures. Multiple image analysis techniques, which could be applicable for a variety of fields needing quantitative data on image switching, confirm both improved magnetic switching and an increased population of interfacial spins with increased thickness of the ultrathin La0.7Sr0.3MnO3 layer. The perpendicular orientation of the interfacial spins is also discussed. This work suggests a magnetoelectric dead layer, with reduced interfacial magnetoelectricity when thin magnetic films are present.}, number={50}, journal={JOURNAL OF PHYSICS-CONDENSED MATTER}, author={Huang, C-Y and Zhou, J. and Tra, V. T. and White, R. and Trappen, R. and N'Diaye, A. T. and Spencer, M. and Frye, C. and Cabrera, G. B. and Nguyen, V. and et al.}, year={2015}, month={Dec} }
 @article{agrawal_lin_barth_white_zheng_chopra_gupta_wang_gelatos_mohney_et al._2014, title={Fermi level depinning and contact resistivity reduction using a reduced titania interlayer in n-silicon metal-insulator-semiconductor ohmic contacts}, volume={104}, number={11}, journal={Applied Physics Letters}, author={Agrawal, A. and Lin, J. and Barth, M. and White, R. and Zheng, B. and Chopra, S. and Gupta, S. and Wang, K. and Gelatos, J. and Mohney, S. E. and et al.}, year={2014} }
 @article{white_dickey_2014, title={Mechanical properties and deformation mechanisms of B4C–TiB2 eutectic composites}, volume={34}, ISSN={0955-2219}, url={http://dx.doi.org/10.1016/j.jeurceramsoc.2013.08.012}, DOI={10.1016/j.jeurceramsoc.2013.08.012}, abstractNote={Samples of B4C–TiB2 eutectic are laser processed to produce composites with varying microstructural scales. The eutectic materials exhibit both load dependent and load independent hardness regimes with a transition occurring between 4 and 5 N indentation load. The load-independent hardness of eutectics with a microstructural scale smaller than 1 μm is about 31 GPa, and the indentation fracture toughness (5–10 N indenter load) of the eutectics is 2.47–4.76 MPa m1/2. Indentation-induced cracks are deflected by TiB2 lamellae, and indentation-induced spallation is reduced in the B4C–TiB2 eutectic compared to monolithic B4C. Indentation-induced amorphization in monolithic B4C and the B4C phase of the eutectic is detected using Raman spectroscopy. Sub-surface damage is observed using TEM, including microcracking and amorphization damage in B4C and B4C–TiB2 eutectics. Dislocations are observed in the TiB2 phase of eutectics with an interlamellar spacing of 1.9 μm.}, number={9}, journal={Journal of the European Ceramic Society}, publisher={Elsevier BV}, author={White, Ryan M. and Dickey, Elizabeth C.}, year={2014}, month={Aug}, pages={2043–2050} }
 @article{parish_white_lebeau_miller_2014, title={Response of nanostructured ferritic alloys to high-dose heavy ion irradiation}, volume={445}, ISSN={["1873-4820"]}, DOI={10.1016/j.jnucmat.2013.11.002}, abstractNote={Abstract A latest-generation aberration-corrected scanning/transmission electron microscope (STEM) is used to study heavy-ion-irradiated nanostructured ferritic alloys (NFAs). Results are presented for STEM X-ray mapping of NFA 14YWT irradiated with 10 MeV Pt to 16 or 160 dpa at −100 °C and 750 °C, as well as pre-irradiation reference material. Irradiation at −100 °C results in ballistic destruction of the beneficial microstructural features present in the pre-irradiated reference material, such as Ti–Y–O nanoclusters (NCs) and grain boundary (GB) segregation. Irradiation at 750 °C retains these beneficial features, but indicates some coarsening of the NCs, diffusion of Al to the NCs, and a reduction of the Cr–W GB segregation (or solute excess) content. Ion irradiation combined with the latest-generation STEM hardware allows for rapid screening of fusion candidate materials and improved understanding of irradiation-induced microstructural changes in NFAs.}, number={1-3}, journal={JOURNAL OF NUCLEAR MATERIALS}, author={Parish, Chad M. and White, Ryan M. and LeBeau, James M. and Miller, Michael K.}, year={2014}, month={Feb}, pages={251–260} }
 @article{hussey_white_kirste_mita_bryan_guo_osterman_haidet_bryan_bobea_et al._2014, title={Sapphire decomposition and inversion domains in N-polar aluminum nitride}, volume={104}, ISSN={["1077-3118"]}, DOI={10.1063/1.4862982}, abstractNote={Transmission electron microscopy (TEM) techniques and potassium hydroxide (KOH) etching confirmed that inversion domains in the N-polar AlN grown on c-plane sapphire were due to the decomposition of sapphire in the presence of hydrogen. The inversion domains were found to correspond to voids at the AlN and sapphire interface, and transmission electron microscopy results showed a V-shaped, columnar inversion domain with staggered domain boundary sidewalls. Voids were also observed in the simultaneously grown Al-polar AlN, however no inversion domains were present. The polarity of AlN grown above the decomposed regions of the sapphire substrate was confirmed to be Al-polar by KOH etching and TEM.}, number={3}, journal={APPLIED PHYSICS LETTERS}, author={Hussey, Lindsay and White, Ryan M. and Kirste, Ronny and Mita, Seiji and Bryan, Isaac and Guo, Wei and Osterman, Katherine and Haidet, Brian and Bryan, Zachary and Bobea, Milena and et al.}, year={2014}, month={Jan} }
 @article{sarac_anderson_pearce_railsback_oni_white_hensley_lebeau_melechko_tracy_2013, title={Airbrushed Nickel Nanoparticles for Large-Area Growth of Vertically Aligned Carbon Nanofibers on Metal (Al, Cu, Ti) Surfaces}, volume={5}, ISSN={["1944-8244"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000330016500022&KeyUID=WOS:000330016500022}, DOI={10.1021/am401889t}, abstractNote={Vertically aligned carbon nanofibers (VACNFs) were grown by plasma-enhanced chemical vapor deposition (PECVD) using Ni nanoparticle (NP) catalysts that were deposited by airbrushing onto Si, Al, Cu, and Ti substrates. Airbrushing is a simple method for depositing catalyst NPs over large areas that is compatible with roll-to-roll processing. The distribution and morphology of VACNFs are affected by the airbrushing parameters and the composition of the metal foil. Highly concentrated Ni NPs in heptane give more uniform distributions than pentane and hexanes, resulting in more uniform coverage of VACNFs. For VACNF growth on metal foils, Si micropowder was added as a precursor for Si-enriched coatings formed in situ on the VACNFs that impart mechanical rigidity. Interactions between the catalyst NPs and the metal substrates impart control over the VACNF morphology. Growth of carbon nanostructures on Cu is particularly noteworthy because the miscibility of Ni with Cu poses challenges for VACNF growth, and carbon nanostructures anchored to Cu substrates are desired as anode materials for Li-ion batteries and for thermal interface materials.}, number={18}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Sarac, Mehmet F. and Anderson, Bryan D. and Pearce, Ryan C. and Railsback, Justin G. and Oni, Adedapo A. and White, Ryan M. and Hensley, Dale K. and LeBeau, James M. and Melechko, Anatoli V. and Tracy, Joseph B.}, year={2013}, month={Sep}, pages={8955–8960} }
 @article{dycus_white_pierce_venkatasubramanian_lebeau_2013, title={Atomic scale structure and chemistry of Bi2Te3/GaAs interfaces grown by metallorganic van der Waals epitaxy}, volume={102}, ISSN={["0003-6951"]}, DOI={10.1063/1.4793518}, abstractNote={Here, we report the atomic scale structure and chemistry of epitaxial Bi2Te3 thin films grown via metallorganic chemical vapor deposition on (001) GaAs substrates. Using aberration corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF STEM), we report an atomically abrupt interface spanned by a second phase. Further, we demonstrate that interpretation of HAADF STEM image intensities does not provide an unambiguous interface structure. Combining atomic resolution imaging and spectroscopy, we determine the identity of the interfacial species is found to be consistent with that of a bilayer of Ga–Te that terminates GaAs dangling bonds.}, number={8}, journal={APPLIED PHYSICS LETTERS}, author={Dycus, J. Houston and White, Ryan M. and Pierce, Jonathan M. and Venkatasubramanian, Rama and LeBeau, James M.}, year={2013}, month={Feb} }
 @article{wilson_sun_chi_white_lebeau_lamb_wiley_2013, title={From Core-Shell to Alloys: The Preparation and Characterization of Solution-Synthesized AuPd Nanoparticle Catalysts}, volume={117}, ISSN={["1932-7447"]}, DOI={10.1021/jp404157m}, abstractNote={This article describes the solution-phase synthesis of 4 nm gold nanoparticles with 0.7 atom-thick, 1.9 atom-thick, and 3.8 atom-thick layers of Pd on their surfaces. These well-defined core–shell nanoparticles were deposited on a silica support, calcined, and reduced at 300 °C to create alloyed nanoparticles containing 10.9, 20.2, and 28.5% Pd (w/w). Monometallic Pd nanoparticles sintered during calcination at 300 °C, but no sintering was observed for AuPd nanoparticles. Diffuse reflectance infrared Fourier transform (DRIFT) spectra of adsorbed CO suggests that Au donates d electron density to Pd in the core–shell and alloy structures and confirms the presence of Au and Pd atoms on the surface of the nanoparticles after calcination and reduction. The properties of the AuPd alloy catalysts were tested in the vapor-phase conversion of α-limonene to p-cymene. AuPd nanoparticles containing 20% or more Pd per particle produced p-cymene yields greater than 80%, equivalent to conventional Pd catalysts prepared ...}, number={34}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, author={Wilson, Adria R. and Sun, Keyi and Chi, Miaofang and White, Ryan M. and LeBeau, James M. and Lamb, H. Henry and Wiley, Benjamin J.}, year={2013}, month={Aug}, pages={17557–17566} }
 @article{white_kunkle_haines_dickey_2013, title={Plasma Processing of B4C-TiB2 Eutectic Composite Powders}, volume={96}, ISSN={0002-7820}, url={http://dx.doi.org/10.1111/jace.12431}, DOI={10.1111/jace.12431}, abstractNote={The production of a composite powder of eutectic B4C–TiB2 is demonstrated via an atmospheric plasma processing method. Feedstock material is prepared for plasma processing by mixing and spray drying monolithic B4C and TiB2 to produce a flowable precursor powder. These powders are fed through a plasma torch, where they are melted and actively quenched in flight with argon gas. Plasma processed powders are composed of crystalline B4C and TiB2, with some additional B2O3 oxide phase. The plasma processing method results in the production of monolithic B4C and TiB2 nanoparticles, but some larger particles (generally ≥10 μm in diameter) are shown to contain the traditional lamellar eutectic microstructure. The eutectic interphase spacing ranges from 100 to 650 nm, and the composite microstructure is present through the entire thickness of the eutectic particles. Future work on plasma processing of eutectic powders should focus on methods utilizing passive in‐flight quenching to increase the average particle size.}, number={7}, journal={Journal of the American Ceramic Society}, publisher={Wiley}, author={White, Ryan M. and Kunkle, Jamie M. and Haines, Chris and Dickey, Elizabeth C.}, editor={Fahrenholt, W. G.Editor}, year={2013}, month={Jun}, pages={2050–2053} }
 @article{burch_harris_white_moballegh_li_maria_dickey_2012, title={In situ heating studies of flux grown barium titanate thin films}, volume={18}, url={https://app.dimensions.ai/details/publication/pub.1054927598}, DOI={10.1017/s1431927612009245}, abstractNote={Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.}, number={S2}, journal={Microscopy and Microanalysis}, author={Burch, M.J. and Harris, D. and White, R.M. and Moballegh, A. and Li, J. and Maria, J.P. and Dickey, Elizabeth C.}, year={2012}, pages={1478–1479} }