Structural and electrical characteristics of Sr/Ti nonstoichiometric SrTiO3 ceramics

The structural, dielectric, leakage current and ferroelectric properties of the SrTi1+xO3 (x = −0.06, −0.03, 0, 0.03 and 0.06) ceramics have been investigated. X-ray diffraction and Scanning electron microscope reveal the microstructure of the samples. The Sr/Ti ratio in STO ceramics effectively adjusts their dielectric and the dc leakage behavior. In addition, the room temperature ferroelectricity of the nonstoichiometric STO ceramics is successfully realized by P-E hysteresis loop measurement. It is found that the origins of ferroelectricity for the Ti-rich and Sr-rich STO ceramics are different and may be related to the lattice distortions, the polar nanoregions and antisite-like defects with net local dipoles.