High-temperature X-ray powder diffraction study of the tetragonal-cubic phase transition in nanocrystalline, compositionally homogeneous ZrO2-CeO2 solid solutions

L. M. ACUÑA, R. O. FUENTES, D. G. LAMAS, I. O. FÁBREGAS, N. E. WALSÖE DE RECA, AND A. F. CRAIEVICH

POWDER DIFFRACTION

J C P D S-INT CENTRE DIFFRACTION DATA

Año: 2008 vol. 23 p. 70 - 74

0885-7156

Crystal structure of compositionally homogeneous, nanocrystalline ZrO2–CeO2 solutions was investigated by X-ray powder diffraction as a function of temperature for compositions between 50 and 65 mol % CeO2. ZrO2-50 and 60 mol % CeO2 solid solutions, which exhibit the t´-form of the tetragonal phase at room temperature, transform into the cubic phase in two steps: t´-to-t" followed by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order tetragonal phase at room temperature, transform into the cubic phase in two steps: t´-to-t" followed by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order investigated by X-ray powder diffraction as a function of temperature for compositions between 50 and 65 mol % CeO2. ZrO2-50 and 60 mol % CeO2 solid solutions, which exhibit the t´-form of the tetragonal phase at room temperature, transform into the cubic phase in two steps: t´-to-t" followed by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order tetragonal phase at room temperature, transform into the cubic phase in two steps: t´-to-t" followed by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order 2–CeO2 solutions was investigated by X-ray powder diffraction as a function of temperature for compositions between 50 and 65 mol % CeO2. ZrO2-50 and 60 mol % CeO2 solid solutions, which exhibit the t´-form of the tetragonal phase at room temperature, transform into the cubic phase in two steps: t´-to-t" followed by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order tetragonal phase at room temperature, transform into the cubic phase in two steps: t´-to-t" followed by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order 2. ZrO2-50 and 60 mol % CeO2 solid solutions, which exhibit the t´-form of the tetragonal phase at room temperature, transform into the cubic phase in two steps: t´-to-t" followed by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order t´-to-t" followed by t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order t"-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t-form, transforms directly to the cubic phase. The results suggest that t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order of second order t´-to-t" transition is of first order, but t"-to-cubic seems to be of second order