Estudio mediante espectroscopías ópticas de defectos cristalinos de tipo F en monocristales de circona estabilizados en fase cúbica con Y₂O₃ y CaO

摘要

Photoluminescence, optical absorption and Raman spectra of thermochemically reduced and untreated Y- and Ca-stabilized cubic zirconia has been investigated. The method of moments and configuracional coordinates has been applied to study the origins and mechanisms of the centers responsible for the luminescence. The results indicated the presence of several emission centers which can be associated with anion vacancies and was tentatively assign to intrinsic F centers and extrinsic F-type centers. The effect of the reduction process results in a decrease in Raman activity in the acoustic mode region, a shift in the maximum of the excitation spectra and a decrease and change in the shape of the emission spectra. These variations can be related to a broad absorption band centered at ¿365 nm. The results indicate that the principal effect of the thermochemically reduction is a redistribution of the initial defects and a generation of a non-random arrangement of oxygen vacancies.