Study of tetragonal-cubic phase transition in nanocrystalline ZrO2-CeO2 powders by high-temperature X-ray diffraction

R.O. FUENTES; D.G. LAMAS; I.O. FÁBREGAS; N.E. WALSÖE DE RECA; A.F. CRAIEVICH

2004 Activity Report of the Brazilian Synchrotron Light Laboratory

Laboratorio Nacional de Luz Sincrotron (LNLS)

Año: 2005 p. 399 - 399

1518-0204

The aim of this work was to study the tetragonal-cubic phase transition as function of temperature on nanocrystalline powders of ZrO2-65%mol CeO2 by high-temperature X-ray diffraction employing a synchrotron radiation source. This material was synthesized by the gel-combustion method and the crystallite size was about 10 nm. The evolution of the (112) peak with temperature was studied. The (112) peak is a characteristic reflection of t"-form (pseudo-fluorite), while it is a forbbiden reflection in a fluorite-like structure of the cubic phase. This reflection is related to the displacement of the oxigen anions. By monitoring of this peak it was possible to discriminate between tetragonal and cubic phases and, therefore, analyze the tetragonal-to-cubic phase transition.