A Novel Electron Paramagnetic Resonance Phenomenon in a Barium Stronium Titanate Ceramic

Abstract

The electron paramagnetic resonance (EPR) technique was employed to investigate the point defects in barium strontium titanate ceramics. All samples showed a strong EPR signal with g = 2.000, which was indexed as intrinsic Ti-vacancy defects. In (Ba0.85Sr0.15)TiO3ceramic, which showed a tetragonal symmetry and consisted of the crystallites with average size of ~ 220 nm, a novel EPR powder spectrum was observed - the g-factor of theg= 2.000 signal evolved into ag-tensor, and the two weak signals withg3= ~ 2.6 andg1= ~ 1.6 gradually shifted toward the g2 = 2.000 signal and approached to each other with increasing temperature.