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Full-Text Articles in Materials Science and Engineering
Mixed Electron Emission From Doped Pb(Zr,Ti)O₃ Ceramics: Microstructural Aspects, Weiming Zhang, Wayne Huebner
Mixed Electron Emission From Doped Pb(Zr,Ti)O₃ Ceramics: Microstructural Aspects, Weiming Zhang, Wayne Huebner
Materials Science and Engineering Faculty Research & Creative Works
A mixed type electron emission, i.e., simultaneous ferroelectric and plasma emission, was observed with a negative driving pulse applied to doped Pb(Zr,Ti)O3 ceramics in the absence of any external potential on the electron collector. During these emission studies, significant microstructural changes on the emission surface were observed, and corresponded to the different emission modes. Erosion craters at the edge of the electrode and small particles near these craters reflected the formation of a dense plasma there. Comparatively, cavities, i.e., grain pullouts, accumulated on the bare ferroelectric surface, the frequency of which depended upon its distance from the grid. This …
Mixed Electron Emission From Lead Zirconate-Titanate Ceramics, Weiming Zhang, Wayne Huebner, Stephen E. Sampayan, Mike L. Krogh
Mixed Electron Emission From Lead Zirconate-Titanate Ceramics, Weiming Zhang, Wayne Huebner, Stephen E. Sampayan, Mike L. Krogh
Materials Science and Engineering Faculty Research & Creative Works
Simultaneous ferroelectric and plasma emission from Pb(Zr,Ti)O3 was observed with only a negative driving pulse applied to the sample, and without an extraction potential on the electron collector. Plasma emission was a strong, inconsistent, and self-destructive process. In addition, a positive ion current was detected. Comparatively, ferroelectric emission was a relatively stable self-emission process, exhibiting no apparent delay time, and no positive ion current. The relationship between the switching and emission current of ferroelectric samples measured simultaneously cannot only be used to determine the existence of ferroelectric emission, but can also give direction to choosing suitable ferroelectric materials for …
Metal-Organic Chemical Vapor Deposition Of Sr-Co-Fe-O Films On Porous Substrates, C.-F. Xia, P. Atanasova, Robert W. Schwartz, T. L. Ward
Metal-Organic Chemical Vapor Deposition Of Sr-Co-Fe-O Films On Porous Substrates, C.-F. Xia, P. Atanasova, Robert W. Schwartz, T. L. Ward
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Aerosol-assisted chemical vapor deposition using the b-diketonate precursors Sr(tmhd)2•2H2O, Fe(tmhd)3 and Co(tmhd)3 was investigated for depositing thin films of the mixed-conducting ceramic SrCoyFe1-yO3-d onto porous a-Al2O3 substrates. Single-phase SrCoyFe1-yO3-d perovskite films were obtained at a deposition temperature of 550°C and pressure of 15 mm Hg, whereas deposition at atmospheric pressure produced mixed-phase films. The Co/Fe elemental ratios in the films reflected those in the precursor solution, but the films were depleted in Sr. Reduced-pressure deposition provided a more uniform film morphology than atmospheric-pressure, and led to a supported film which was leak-tight to N2 flow.