Electrochemical vapor deposition of doped LaCrO{sub 3}

Conference · Sun Dec 31 00:00:00 EST 1995

OSTI ID:242552

Dieten, V E.J. van; Schoonman, J ^[1]

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1. Delft Univ. of Technology (Netherlands). Lab. for Applied Inorganic Chemistry

CVD/EVD of Mg-doped LaCrO{sub 3} on porous calcia-stabilized zirconia (CSZ) has been investigated in the temperature range of 1,473 to 1,523 K using the metal chlorides as reactants. During the EVD stage, doped LaCrO{sub 3} is formed as long as the supply of LaCl{sub 3} is sufficient, otherwise Cr{sub 2}O{sub 3} will be formed simultaneously. The magnesium content of the LaCrO{sub 3} films is very low (< 2%), despite the excess of MgCl{sub 2} in the reactant stream, as expected from thermodynamic calculations. Film growth shows parabolic behavior, indicating that the deposition is controlled by solid state diffusion. The parabolic growth rate constant is determined to be 8.2{times}10{sup {minus}11} cm{sup 2}/s at 1,473 K, and 1.1{times}10{sup {minus}10} cm{sup 2}/s at 1,523 K. Dense films of doped LaCrO{sub 3} can also be grown by the EVD process on gas tight oxygen ion conducting substrates. Sr-doped LaCrO{sub 3} has been deposited on gas tight YSZ at a temperature of about 1,413 K. The metal chlorides were generated by chlorination of the metals with HCl. Like magnesium, strontium is difficult to incorporate into EVD grown LaCrO{sub 3} films, as the presence of strontium was not confirmed using EDX analysis. At a temperature of 1,410 K, film growth on 200 to 600 {micro}m thick YSZ substrates is parabolic beyond 2 {micro}m film thickness, indicating that the reaction is solely determined by solid state diffusion through the growing film. The parabolic growth rate constant at that temperature is determined to be 6.5{times}10{sup {minus}11}cm{sup 2}/s.

• OSTI ID: 242552
• Report Number(s): CONF-950683-; ISBN 1-56677-095-5; TRN: IM9626%%380
• Resource Relation: Conference: 4. international symposium on solid oxide fuel cells, Yokohama (Japan), 18-23 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the fourth international symposium on solid oxide fuel cells (SOFC-IV). Proceedings Volume 95-1; Dokiya, M. [ed.] [National Inst. of Materials and Chemical Research, Tsukuba, Ibaraki (Japan)]; Yamamoto, O. [ed.] [Mie Univ., Tsu, Mie (Japan)]; Tagawa, H. [ed.] [Yokohama National Univ., Yokohama, Kanagawa (Japan)]; Singhal, S.C. [ed.] [Westinghouse Electric Corp., Pittsburgh, PA (United States)]; PB: 1188 p.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
30 DIRECT ENERGY CONVERSION
LANTHANUM OXIDES
ELECTROCHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
CHROMIUM OXIDES
MAGNESIUM OXIDES
SOLID ELECTROLYTE FUEL CELLS
MATERIALS
STRONTIUM OXIDES
CONNECTORS
ZIRCONIUM OXIDES
CALCIUM OXIDES
VAPOR DEPOSITED COATINGS
CHEMICAL REACTION KINETICS
PRECURSOR
YTTRIUM OXIDES
SCANNING ELECTRON MICROSCOPY
PERMEABILITY
THICKNESS