Improved electrical properties of Pr-doped films

Sr1−xPrxTiO3 films were prepared by metal organic deposition method on (111) Pt/Ti/SiO2/Si substrates. Pr-doping greatly improves the dc leakage behavior of the films. The samples with x = 0.075 show excellent electric field frequency and temperature stability of dielectric properties, while the x = 0.025 samples indicate an obvious dielectric relaxation behavior and better polarization versus applied electric field ( P – E ) hysteresis loops. These peculiar electrical properties can be explained mainly by the Pr-doping-induced changes in the free charge carriers, the lattice distortion, the charge transfer process and polar nanoregions. In addition, the variable valence of Pr ions may also have significant impacts.