Crystallization Of Oxide Films Derived From Metallo-Organic Precursors

Abstract

ABSTRACTFerroelectric lead zirconate titanate and ferrimagnetic nickel ferrite films were prepared by dip-coating of metal organic solutions. In the amorphous state, both films were porous, with specific porous surface areas on the order of tens of square meters. Crystallization temperatures were in the range of 400–500°C. The crystallization kinetics of the porous films and powders of both compounds have been studied by using non-isothermal DSC and isothermal XRD. The kinetic parameters were empirically described by the Johnson-Mehl-Avrami transformation equation α = 1- exp(−Ktn). The order of reaction (n) of PZT film is approximately 1 but that of the powder is 2, and their activation energies are 80 and 70 kcal/mole, respectively. It was found that the PZT film crystallizes more easily than the powder at the same temperature. The nickel ferrite film and powder, on the other hand, have similar n values ranging from 0.6 to 0.7, with activation energies of 20 and 35 kcal/mole, respectively. The possible mechanisms were also briefly discussed.