Polar behavior in Mn-doped SrTiO3 ceramics

Polar behavior was found in Sr1−xMnxTiO3(x=0.005–0.02) ceramic system. Radio-frequency dielectric measurements showed a diffuse maximum at 25–65 K shifting to higher temperatures with increasing measurement frequency and amount of Mn. The observation of hysteretic behavior in the P versus E curves shows the existence of a polar state at low temperatures. The hysteresis response slowly degenerates into just nonlinearity as the temperature increases. The observed relaxor-type dielectric behavior is attributed to the formation of electric dipoles and corresponding random fields due to the off-center position of Mn2+ ion at the Sr site of highly polarizable SrTiO3 lattice.