Structural and dielectric properties of BaTiO3 - BiScO3 ceramics

The structural and dielectric properties of bulk (1??x) BaTiO3??x BiScO3 (x = 0 ?? 0.6) ceramics were investigated to acquire a better understanding of the binary system, including determination of the phase diagram, dielectric properties, and the difference in roles of Bi and BiScO3 doping on BaTiO3. The solubility limit for BiScO3 into the BaTiO3 perovskite structure was determined to be about x = 0.4, which was much higher than the solubility of Bi alone. A structural change from tetragonal to pseudocubic was observed at about x = 0.05 ?? 0.1 at room temperature. Dielectric measurements revealed the gradual change from typical ferroelectric behavior in pure BaTiO3 to a highly diffusive and dispersive relaxor behavior from 10 to 40 mol% BiScO3. Several of the compositions showed high permittivities (approximately 1000) with low temperature coefficients of capacitance.