Kinetics of the Anatase-Rutile Transformation in TiO2 in the presence of Fe2O3

F. C. GENNARI; D. M. PASQUEVICH

JOURNAL OF MATERIALS SCIENCE

SPRINGER

Lugar: Berlin; Año: 1998 vol. 33 p. 1571 - 1578

0022-2461

The anatase–rutile phase transition in TiO2 in the presence of Fe2O3 was investigated in air and argon atmospheres by means of X-ray diffraction and scanning electron microscopy. Isothermal curves of rutile transformed from anatase as a function of time were obtained between 825 and 950 °C. The data were well fitted by various rate laws. In the presence of Fe3+, the anatase–rutile transition temperature is lower and the transformation rate in air is higher than the corresponding one in pure TiO2. The transformation in the presence of Fe3+ in an argon atmosphere is more rapid than in air. The enhancement effect of Fe3+ on the anatase–rutile transformation in both atmospheres is understood on the basis of the formation of oxygen vacancies.