Segregation in Single-Crystal Fully Stabilized Yttria-Zirconia |
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Authors: | Anthony E Hughes |
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Affiliation: | C.S.I.R.O. Division of Materials Science and Technology, Clayton, Victoria, 3169, Australia |
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Abstract: | X-ray photoelectron spectroscopy (XPS) has been used to study surface segregation in 9.5 mol% single-crystal Y2O3-ZrO2 which has been subjected to air anneals at temperatures ranging from 900° to 1500°C. The kinetics of segregation reveal an enrichment of Y, Si, Na, and Fe at short times; however, at longer times surface equilibrium is reached. The heats of segregation for Y, Si, Na and Fe, determined from Arrhenius plots, were 9.3 ± 3.0, 59.0 ± 7.0, –23.5 ± 11.5, –18.0 ± 6.0 kJ/mol, respectively. XPS analysis of the equilibrium states at all temperatures revealed a distinct surface layer which, given the positive heats of segregation for Si and Y, is quite stable. |
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