Nanostructures in yttria stabilized hafnia films observed by PAC

M. C. CARACOCHE; J. A. MARTÍNEZ; P. C. RIVAS; M. A. TAYLOR; A. F. PASQUEVICH; C. Y. CHAIN; S. BAROLIN; O. A. DE SANCTIS

Puerto Iguazú, Argentina

Simposio; XIX Latin American Symposium on Solid State Physics; 2008

Thin film of stabilized hafnia with 10 and 12 mole % of yttira obtained by sol-gel and dip-coating have been studied by in-situ x ray diffraction (XRD) up to 1300C and by Perturbed Angular Correlations (PAC) as a function of temperature up to 1130C. Powders of identical compositions have been also investigated with the aim of comparing the phase stability in both types of materials. XRD results indicate that the as-prepared films stabilize in the cubic form which maintains up to the annealing temperature of 1000C. When cooling from 1300C, the film with 10 mole  % of yttria is strongly destabilized into monoclinic hafnia. Powders retain the cubic phase all over the investigated thermal range but traces of monoclinic hafnia are detected in the less concentrated sample. Preliminary PAC results on films do not show any change of the nanoconfigurations content up to 500C. Measurements at higher temperatures are in progress.