IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Thermal study of the local structures in a HfO2-14 mol % CaO film
Autor/es:
M.A. TAYLOR, P.C. RIVAS, O. DE SANCTIS, A.M. RODRIGUEZ, A.F. PASQUEVICH, J.A. MARTINEZ AND M.C. CARACOCHE
Lugar:
Bariloche, Argentna
Reunión:
Conferencia; 13th International Conference on Solid Films and Surface; 2006
Resumen:
A film of HfO2-14 mol% CaO prepared
by sol-gel has been grown onto Al2O3 by deep coating. The
thermal behavior of the film is investigated by using Differential Thermal
Analyses (DTA-TGA), X-ray diffraction (XRD) as a function of annealing
temperatures and the Perturbed Angular Correlation (PAC) technique in-
temperature and after annealing. XRD experiments were performed in air, DTA in
air and Ar and PAC in air and vacuum.
The as-prepared film exhibits a cubic structure
(XRD) and a predominant cubic hyperfine interaction (PAC in air). PAC results
in air also show the existence of two other components, one of them associated
to CaHf4O9 and the other, unknown. The thermal evolution
of the starting phase content evolved to the appearance of the monoclinic phase
above 800ºC
in agreement with subtle changes observed in DTA recorded in air. The
differences between PAC results in air and vacuum and between DTA in air and
Ar, allowed interpreting the unknown interaction as due to processes occurring
at the free surface of the film and also to understand why, in vacuum, the
monoclinic phase does not appear.