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Title: Deposition of crystals from the plasmas of ZrO/sub 2/, HfO/sub 2/, ThO/sub 2/, and CeO/sub 2/

Abstract

Deposition occurs onto a cathode from an oxide plasma generated inside a hollow oxide anode by the mechanism called the electrolysis of plasma. The temperature of the cathode is usually over 2000 /sup 0/C during deposition. Deposits attain fairly large crystalline sizes (about 0.3 mm) in spite of their high deposition rates. And besides, some unusual crystals are formed. For the deposition from ZrO/sub 2/, HfO/sub 2/, and ThO/sub 2/ plasmas, the deposition rate, growth rate, and the current efficiency increase with the plasma current (0.4--8 A) and with feeding O/sub 2/ gas into the plasmas. On the other hand, heating a cathode externally or feeding Ar gas into them leads to the reduction of those rates, the current efficiency, and yield. The maximum growth rate from the ThO/sub 2/ plasma is 8.4 ..mu..m/sec. Yields exceed 90% in general. Mass-spectrometric analyses showed that the main depositing ion species is ZrO/sup +/ for the deposition from the ZrO/sub 2/ plasma. Deposits obtained are usually black oxides, whose O/M (M=Zr, Hf, and Th) ratios are 1.95, 1.95, and 1.64, respectively. The deposits from ZrO/sub 2/, HfO/sub 2/, and ThO/sub 2/ plasmas are monoclinic ZrO/sub 2/ with precipitates of metallic ..cap alpha..-Zr, monoclinicmore » HfO/sub 2/ with a small amount of unknown hexagonal crystals (whose lattice parameters are a=3.17 and c=5.02 A), and a mixture of fcc ThO/sub 2/ and Th, respectively. When O/sub 2/ gas is fed into those plasmas, transparent oxide crystals of stoichiometric composition are formed. The deposits from a CeO/sub 2/ plasma are the black oxides whose O/Ce ratios are 1.53 on the average. Contrary to the phase diagram of the Ce-O system, they show x-ray structures of fcc crystals whose lattice parameter varies from 5.506 to 5.411 A.« less

Authors:
;
Publication Date:
Research Org.:
Institute of Atomic Energy, Kyoto University, Kyoto, Japan
OSTI Identifier:
5920864
Resource Type:
Journal Article
Journal Name:
J. Appl. Phys.; (United States)
Additional Journal Information:
Journal Volume: 50:10; Journal Issue: 10
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CERIUM OXIDES; DEPOSITION; HAFNIUM OXIDES; THORIUM OXIDES; ZIRCONIUM OXIDES; ANODES; EFFICIENCY; ELECTRIC CURRENTS; ELECTROLYSIS; GASES; OXYGEN; PLASMA HEATING; VERY HIGH TEMPERATURE; ACTINIDE COMPOUNDS; CERIUM COMPOUNDS; CHALCOGENIDES; CRYOGENIC FLUIDS; CURRENTS; ELECTRODES; ELEMENTS; FLUIDS; HAFNIUM COMPOUNDS; HEATING; LYSIS; NONMETALS; OXIDES; OXYGEN COMPOUNDS; RARE EARTH COMPOUNDS; THORIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS; ZIRCONIUM COMPOUNDS; 360201* - Ceramics, Cermets, & Refractories- Preparation & Fabrication

Citation Formats

Kawabuchi, K, and Magari, S. Deposition of crystals from the plasmas of ZrO/sub 2/, HfO/sub 2/, ThO/sub 2/, and CeO/sub 2/. United States: N. p., 1979. Web. doi:10.1063/1.325757.
Kawabuchi, K, & Magari, S. Deposition of crystals from the plasmas of ZrO/sub 2/, HfO/sub 2/, ThO/sub 2/, and CeO/sub 2/. United States. doi:10.1063/1.325757.
Kawabuchi, K, and Magari, S. Mon . "Deposition of crystals from the plasmas of ZrO/sub 2/, HfO/sub 2/, ThO/sub 2/, and CeO/sub 2/". United States. doi:10.1063/1.325757.
@article{osti_5920864,
title = {Deposition of crystals from the plasmas of ZrO/sub 2/, HfO/sub 2/, ThO/sub 2/, and CeO/sub 2/},
author = {Kawabuchi, K and Magari, S},
abstractNote = {Deposition occurs onto a cathode from an oxide plasma generated inside a hollow oxide anode by the mechanism called the electrolysis of plasma. The temperature of the cathode is usually over 2000 /sup 0/C during deposition. Deposits attain fairly large crystalline sizes (about 0.3 mm) in spite of their high deposition rates. And besides, some unusual crystals are formed. For the deposition from ZrO/sub 2/, HfO/sub 2/, and ThO/sub 2/ plasmas, the deposition rate, growth rate, and the current efficiency increase with the plasma current (0.4--8 A) and with feeding O/sub 2/ gas into the plasmas. On the other hand, heating a cathode externally or feeding Ar gas into them leads to the reduction of those rates, the current efficiency, and yield. The maximum growth rate from the ThO/sub 2/ plasma is 8.4 ..mu..m/sec. Yields exceed 90% in general. Mass-spectrometric analyses showed that the main depositing ion species is ZrO/sup +/ for the deposition from the ZrO/sub 2/ plasma. Deposits obtained are usually black oxides, whose O/M (M=Zr, Hf, and Th) ratios are 1.95, 1.95, and 1.64, respectively. The deposits from ZrO/sub 2/, HfO/sub 2/, and ThO/sub 2/ plasmas are monoclinic ZrO/sub 2/ with precipitates of metallic ..cap alpha..-Zr, monoclinic HfO/sub 2/ with a small amount of unknown hexagonal crystals (whose lattice parameters are a=3.17 and c=5.02 A), and a mixture of fcc ThO/sub 2/ and Th, respectively. When O/sub 2/ gas is fed into those plasmas, transparent oxide crystals of stoichiometric composition are formed. The deposits from a CeO/sub 2/ plasma are the black oxides whose O/Ce ratios are 1.53 on the average. Contrary to the phase diagram of the Ce-O system, they show x-ray structures of fcc crystals whose lattice parameter varies from 5.506 to 5.411 A.},
doi = {10.1063/1.325757},
journal = {J. Appl. Phys.; (United States)},
number = 10,
volume = 50:10,
place = {United States},
year = {1979},
month = {10}
}