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Materials Science and Engineering Faculty Research & Creative Works

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Thin films

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Full-Text Articles in Engineering

Impact Of Symmetry On The Ferroelectric Properties Of Catio₃ Thin Films, Michael D. Biegalski, Liang Qiao, Yijia Gu, Apurva Mehta, Qian He, For Full List Of Authors, See Publisher's Website. Apr 2015

Impact Of Symmetry On The Ferroelectric Properties Of Catio₃ Thin Films, Michael D. Biegalski, Liang Qiao, Yijia Gu, Apurva Mehta, Qian He, For Full List Of Authors, See Publisher's Website.

Materials Science and Engineering Faculty Research & Creative Works

Epitaxial strain is a powerful tool to induce functional properties such as ferroelectricity in thin films of materials that do not possess ferroelectricity in bulk form. In this work, a ferroelectric state was stabilized in thin films of the incipient ferroelectric, CaTiO3, through the careful control of the biaxial strain state and TiO6 octahedral rotations. Detailed structural characterization was carried out by synchrotron x-ray diffraction and scanning transmission electron microscopy. CaTiO3 films grown on La0.18Sr0.82Al0.59Ta0.41O3 (LSAT) and NdGaO3 (NGO) substrates experienced a 1.1% biaxial strain state …


Nonstoichiometry And Electrical Transport In Sc-Doped Zirconia, Igor Kosacki, Harlan U. Anderson, Yasunobu Mizutani, Kenji Ukai Dec 2002

Nonstoichiometry And Electrical Transport In Sc-Doped Zirconia, Igor Kosacki, Harlan U. Anderson, Yasunobu Mizutani, Kenji Ukai

Materials Science and Engineering Faculty Research & Creative Works

The results of electrical conductivity measurements on ZrO2: Sc (ScSZ) ceramics as a function of oxygen activity and temperature are presented. The influence of the microstructure on electrical transport is discussed and the experimental data for dense microcrystalline specimens have been compared with those obtained for dense nanocrystalline thin films. From these results the electronic and ionic contribution to the electrical transport has been determined and correlated with microstructure. It has been found that nanocrystalline ScSZ films possess quite different nonstoichiometry compared with that observed for microcrystalline specimens in the fact that the electronic conductivity is enhanced so …


Microstructure-Electrical Conductivity Relationships In Nanocrystalline Ceria Thin Films, Toshio Suzuki, Igor Kosacki, Harlan U. Anderson Nov 2002

Microstructure-Electrical Conductivity Relationships In Nanocrystalline Ceria Thin Films, Toshio Suzuki, Igor Kosacki, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

A study of nanocrystalline oxide thin film processing and influence of microstructure on the electrical properties of nanocrystalline Gd3+-doped CeO2 thin films was reported. Nanocrystalline films on sapphire substrate were prepared using a polymeric precursor spin coating technique. The grain size of these films depends upon the annealing temperatures and the dopant content, where higher content of dopant realized smaller grain size. The electrical conductivity of nanocrystalline Gd3+-doped CeO2 thin films was studied as a function of temperature and oxygen activity and correlated with the grain size. The results show that the electronic conductivity …


Raman Scattering And Lattice Defects In Nanocrystalline Ceo2 Thin Films, Igor Kosacki, Toshio Suzuki, Harlan U. Anderson, Philippe Colomban Jul 2002

Raman Scattering And Lattice Defects In Nanocrystalline Ceo2 Thin Films, Igor Kosacki, Toshio Suzuki, Harlan U. Anderson, Philippe Colomban

Materials Science and Engineering Faculty Research & Creative Works

The results of Raman scattering studies of nanocrystalline CeO2 thin films are presented. The spectra have been described using the spatial correlation model from which the correlation length has been determined as a function of grain size. A direct comparison between the concentration of defects related to correlation length and CeO2 non-stoichiometry has been achieved. The relationship between the lattice disorder and the form of the Raman spectra in nanocrystalline CeO2 is discussed. © 2002 Elsevier Science B.V. All rights reserved.


Intermetallic Reactions In Vacuum-Deposited Nickel And Gold Films On (111) Silicon Single Crystals, K. H. Yoon, Gordon Lewis, L. L. Levenson Apr 1976

Intermetallic Reactions In Vacuum-Deposited Nickel And Gold Films On (111) Silicon Single Crystals, K. H. Yoon, Gordon Lewis, L. L. Levenson

Materials Science and Engineering Faculty Research & Creative Works

Pure nickel and gold thin films were vacuum-deposited on (111) silicon single crystals. When Ni/Au/Si or Au/Ni/Si samples were heated to about 550° in situ, hexagonal or deformed hexagonal shaped crystallites were formed on the silicon substrates. The composition of these crystallites was determined by using x-ray diffraction, scanning electron microscopy and scanning Auger microprobe methods. The crystallites were identified as NiSi2. The crystal-lites on the (111) silicon plane parallel to the surface appeared as regular hexagons while the inclined crystal-lites resembled trapezia. The results of Auger spectra and in-depth composition profiles for Ni, Au, and Si showed that the …