The influence of intense ultrasound applied during pressing on the optical and cathodoluminescent properties of conventionally sintered YSZ ceramics

The aim of the present work was to investigate the effect of the ultrasonic treatment on the optical and cathodoluminescent properties of translucent ZrO2-8 mol.% Y2O3 (YSZ) ceramics obtained by conventional sintering of the pressed compacts. Treatment by intense ultrasound during dry pressing of the YSZ nanopowder leads to an increase in the relative density, a decrease in the pore size and an increase in the grain size of the sintered ceramics. It was shown that when the ultrasonic treatment is applied, the optical absorption cutoff wavelength of the sintered material is shifted to longer wavelengths, while the optical density of the material increases over the whole measurement spectrum. Samples subjected to ultrasonic treatment during pressing show higher intensity of luminescence than those obtained without the use of ultrasound, the shape of the luminescence spectra remaining unchanged. A correlation was obtained between the integral intensity of cathodoluminescence and the vacancy concentration in the sintered YSZ.