Dielectric Properties of Samarium Substituted Barium Strontium Titanate

The effect of samarium substitution on dielectric and ferroelectric properties of BST is studied. Sample with compositional formula [Ba_0.95Sr_0.05]_1−x/2Sm_xTi_1−x/2O₃, with x varying from 0 to 0.025 in steps of 0.005, were prepared by the conventional dry method. X-ray analysis confirmed the formation of single-phase compound in the tetragonal crystal system. Dielectric properties were studied in detail as a function of frequency and temperature. Variation of dielectric constant with temperature shows a ferroelectric phase transition, and the transition temperature decreases with increasing samarium content. The activation energy for d.c. and a.c. conduction were determined from the variation of conductivity with temperature.