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Deviation from Stoichiometry in Cr 2 O 3 at High Oxygen Partial Pressures
Author(s) -
Greskovich C.
Publication year - 1984
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1984.tb19712.x
Subject(s) - stoichiometry , analytical chemistry (journal) , diffusion , chromium , oxygen , vacancy defect , chemistry , materials science , mineralogy , thermodynamics , crystallography , metallurgy , chromatography , physics , organic chemistry
The deviation from stoichiometry, δ, in Cr 2 −δO 3 was measured by a tensivolumetric method in the high pO 2 range of ≊10 4 to 10 4 Pa at 1100°C. The value of δ, or chromium vacancy concentration, was≊9×10 −5 mol/mol Cr 2 O 3 in air for Cr 2 O 3 with 99.999% purity. The chemical diffusion coefficient, DT, determined from equilibration data was ≊4.6× cm 2 ·s −1 at 1100°C for pO 2 = 2.2 ×10 1 Pa. The self‐diffusion coefficient of Cr ions was calculated from and δ and found to be≊1.6×10‐17 cm 2 ‐s −1 , in good agreement with recently measured values.