Effect of zirconia on the structural and optical properties of strontium titanate ceramic

Sr(ZrxTi1-x)O3 (SZT) powders were prepared by using a planetary ball milling unit. Compositionally induced phase transitions in SZT system were analysed using a combination of X-ray diffraction and FT-Raman. The system showed two tilting of phase transitions, pm3m–I4mcm and I4/mcm–pnma. The optical band gap of the system was calculated from the reflectance data recorded from a UV-Vis spectrometer using Kubelkae-Munk equation. The width of defect bands (Urbach energy) was determined from the reflectance data. The optical band gap increased from 3.04 eV to 5.13 eV with increase of x content. The Photoluminescence analysis of all compositions showed Violet-blue-green emission.