@article{oktyabrsky_dovidenko_sharma_joshkin_narayan_1999, title={Crystal structure and defects in nitrogen-deficient GaN}, volume={4S1}, number={G6.43}, journal={MRS Internet Journal of Nitride Semiconductor Research}, author={Oktyabrsky, S. and Dovidenko, K. and Sharma, A. K. and Joshkin, V. and Narayan, J.}, year={1999} }
 @article{oktyabrsky_dovidenko_sharma_narayan_joshkin_1999, title={Cubic GaN formation under nitrogen-deficient conditions}, volume={74}, ISSN={["0003-6951"]}, DOI={10.1063/1.123882}, abstractNote={We have studied crystal structure and associated defects in GaN/α-Al2O3 (0001) films grown under nitrogen-deficient conditions by metalorganic chemical vapor deposition and pulsed laser deposition. N-deficient films exhibit polycrystalline structure with a mixture of cubic zinc-blende and wurtzite hexagonal GaN grains retaining tetragonal bonding across the boundaries and hence the epitaxial orientations and polarity. Renucleation of the wurtzite phase at different {111} planes of cubic GaN results in a rough and faceted surface of the film. We elucidate that the cubic phase is more stable under the nitrogen deficiency.}, number={17}, journal={APPLIED PHYSICS LETTERS}, author={Oktyabrsky, S and Dovidenko, K and Sharma, AK and Narayan, J and Joshkin, V}, year={1999}, month={Apr}, pages={2465–2467} }
 @article{dovidenko_oktyabrsky_narayan_razeghi_1999, title={Study of thin films polarity of group III nitrides}, volume={4S1}, number={G6.46}, journal={MRS Internet Journal of Nitride Semiconductor Research}, author={Dovidenko, K. and Oktyabrsky, S. and Narayan, J. and Razeghi, M.}, year={1999} }
 @article{godbole_dovidenko_sharma_narayan_1999, title={Thermal reactions and micro-structure of TiN-AlN layered nano-composites}, volume={68}, ISSN={["0921-5107"]}, DOI={10.1016/s0921-5107(99)00154-3}, abstractNote={Bilayer and multilayer structures of TiN and AlN thin films were synthesized using pulsed laser deposition technique in a substrate temperature range 300–700°C. The chemical reactions at TiN–AlN interfaces and the formation of different alloy phases were studied using X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was observed that TiN–AlN interface remains sharp and stable for deposition temperatures up to ∼650°C. At higher deposition temperatures, however, substantial chemical reactions were found to occur. The ternary alloy phases such as Ti3Al2N2 and Ti3AlN have been observed, for the first time. The composites synthesized at temperatures lower than 650°C and subsequently annealed at higher temperature were found to exhibit very limited or no interfacial chemical reactions. The effect of layer thickness on the microstructure is also studied. The studies revealed that by controlling the thickness of individual layers and substrate temperatures, it was possible to control microstructure and obtain composite coatings consisting of ternary Ti–Al–N alloy phases. The results are discussed in terms of characteristic features of pulsed laser ablation process in which evaporated flux contains energetic ions, electrons and neutral particles. Preliminary nano-indentation measurements and oxidation measurements reveal that these composites possess desirable mechanical properties at high temperatures.}, number={2}, journal={MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY}, author={Godbole, VP and Dovidenko, K and Sharma, AK and Narayan, J}, year={1999}, month={Dec}, pages={85–90} }
 @article{narayan_dovidenko_sharma_oktyabrsky_1998, title={Defects and interfaces in epitaxial ZnO/alpha-Al2O3 and AlN/ZnO/alpha-Al2O3, heterostructures}, volume={84}, ISSN={["0021-8979"]}, DOI={10.1063/1.368440}, abstractNote={We have investigated the nature of epitaxy, defects (dislocations, stacking faults, and inversion domains), and heterointerfaces in zinc oxide films grown on (0001) sapphire and explored the possibility of using it as a buffer layer for growing group III nitrides. High quality epitaxial ZnO films were grown on sapphire using pulsed laser deposition in the temperature range 750–800 °C. The epitaxial relationship of the film with respect to (0001) sapphire was found to be (0001)ZnO∥(0001)sap, with in-plane orientation relationship of [011̄0]ZnO∥[1̄21̄0]sap. This in-plane orientation relationship corresponds to a 30° rotation of ZnO basal planes with respect to the sapphire substrate, which is similar to the epitaxial growth characteristics of AlN and GaN on sapphire. The threading dislocations in ZnO were found to have mostly 1/3〈112̄0〉 Burgers vectors. The planar defects (mostly I1 stacking faults) were found to lie in the basal plane with density of about 105 cm−1. We have grown epitaxial AlN films at temperatures around 770 °C using ZnO/sapphire heterostructure as a substrate and observed the formation of a thin reacted layer at the AlN/ZnO interface. The implications of low defect content in ZnO films compared to III–V nitrides and the role of ZnO films as a buffer layer for III–V nitrides are discussed.}, number={5}, journal={JOURNAL OF APPLIED PHYSICS}, author={Narayan, J and Dovidenko, K and Sharma, AK and Oktyabrsky, S}, year={1998}, month={Sep}, pages={2597–2601} }
 @inproceedings{sharma_dovidenko_oktyabrsky_moxey_muth_kolbas_narayan_1998, title={Growth of high quality single crystal ZnO films on sapphire by pulsed laser ablation}, booktitle={Advances in laser ablation of materials: Symposium held April 13-16, 1998, San Francisco, California, U.S.A.  (Materials Research Society symposia proceedings ; v. 526).}, publisher={Warrendale, Pa.: Materials Research Society}, author={Sharma, A. K. and Dovidenko, K. and Oktyabrsky, S. and Moxey, D. E. and Muth, J. F. and Kolbas, R. M. and Narayan, J.}, year={1998}, pages={305} }
 @article{tsu_filios_lofgren_dovidenko_wang_1998, title={Silicon epitaxy on Si(100) with adsorbed oxygen}, volume={1}, number={2}, journal={Electrochemical and Solid State Letters}, author={Tsu, R. and Filios, A. and Lofgren, C. and Dovidenko, K. and Wang, C. G.}, year={1998}, pages={80–82} }
 @article{dovidenko_oktyabrsky_narayan_1997, title={Characteristics of stacking faults in AlN thin films}, volume={82}, ISSN={["0021-8979"]}, DOI={10.1063/1.366236}, abstractNote={We have investigated growth characteristics and atomic structure of defects in AlN thin films grown by the metalorganic chemical vapor deposition technique on the (101̄2) r plane of α-Al2O3. The AlN films were single crystal and exhibited the following epitaxial relationship: (112̄0)AlN∥(101̄2)sap with the in-plane alignment of [0001]AlN∥[1̄011]sap. Using high-resolution electron microscopy and multislice image simulation, the predominant defects in AlN thin films grown on the r plane of α-Al2O3 were found to be low-energy intrinsic stacking faults of type I1 lying in the basal plane. This fault, with a 1/6[202̄3] resultant displacement vector, can be formed by removing one (0002) plane and then shearing the remaining half-crystal by displacement of 1/3[101̄0]. The faults appear as a single face-centered-cubic stack ABC inserted into the normal …ABAB… hexagonal sequence. We discuss the possible role of these defects in optical properties of semiconductor devices.}, number={9}, journal={JOURNAL OF APPLIED PHYSICS}, author={Dovidenko, K and Oktyabrsky, S and Narayan, J}, year={1997}, month={Nov}, pages={4296–4299} }
 @article{kalyanaraman_vispute_oktyabrsky_dovidenko_jagannadham_narayan_budai_parikh_suvkhanov_1997, title={Influence of oxygen background pressure on crystalline quality of SrTiO3 films grown on MgO by pulsed laser deposition}, volume={71}, ISSN={0003-6951 1077-3118}, url={http://dx.doi.org/10.1063/1.120011}, DOI={10.1063/1.120011}, abstractNote={We have systematically investigated the effect of oxygen partial pressure (PO2) on the crystalline quality of SrTiO3 films grown on MgO (001) substrates using pulsed laser deposition and established optimized conditions for the growth of high-quality epitaxial films. The crystalline quality is found to improve significantly in the O2 pressure range of 0.5–1 mTorr, compared to the films deposited at higher pressures of 10–100 mTorr. The x-ray diffraction rocking curves for the films grown at PO2 of 1 mTorr and 100 mTorr yielded full width at half-maximum (FWHM) of 0.7° and 1.4°, respectively. The in-plane x-ray φ scans showed epitaxial cube-on-cube alignment of the films. Channeling yields χmin were found to be <5% for the 1 mTorr films and ∼14% for 100 mTorr films. Thermal annealing of the SrTiO3 films in oxygen further improves the quality, and the 1 mTorr films give FWHM of 0.13° and χmin of 1.7%. In-plane misorientations of the annealed SrTiO3 films calculated using results of transmission electron microscopy are ±0.7° for 1 mTorr and ±1.7° for the 10 mTorr film. The high temperature superconducting (high-Tc) Y1Ba2Cu3O7−δ films grown on these SrTiO3/MgO substrates showed a χmin of 2.0% and transition temperature of ∼92 K, indicating that SrTiO3 buffer layers on MgO can be used for growth of high-quality Y1Ba2Cu3O7−δ thin film heterostructures for use in high-Tc devices and next generation microelectronics devices requiring films with high dielectric constants.}, number={12}, journal={Applied Physics Letters}, publisher={AIP Publishing}, author={Kalyanaraman, R. and Vispute, R. D. and Oktyabrsky, S. and Dovidenko, K. and Jagannadham, K. and Narayan, J. and Budai, J. D. and Parikh, N. and Suvkhanov, A.}, year={1997}, month={Sep}, pages={1709–1711} }