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Effect of different cooling rates on Cr segregation and determination of the equilibration time of Cr segregation in CoOCr 2 O 3 and NiOCr 2 O 3 solid solutions
Author(s) -
Hirschwald W.,
Stolze F.,
Sikora I.
Publication year - 1992
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.740180406
Subject(s) - annealing (glass) , non blocking i/o , chromium , materials science , analytical chemistry (journal) , argon , quenching (fluorescence) , slow cooling , metallurgy , chemistry , chromatography , biochemistry , physics , organic chemistry , quantum mechanics , fluorescence , catalysis
CoO and NiO single crystals doped with chromium were either quenched or slowly cooled after 1 week of annealing at 1150° C and 1200° C in argon. SIMS analysis of the Cr surface distribution revealed a remarkably high Cr concentration in the near‐surface layers of slowly cooled samples and a much smaller concentration for the quenched crystals. The differences of surface Cr concentration in various quenching procedures are also shown. By applying subequilibrium annealing times, different Cr segregation levels and varying thicknesses of surface layers could be established. The time of annealing necessary to obtain equilibrium of segregation was determined for both solid solutions.