Improvement of electrical properties in Bi compensated 0.33BaTiO3-0.67BiFeO3 ceramics prepared via spark plasma sintering

In the present work, 0.33BaTiO3-0.67BiFeO3-xBi2O3 ceramics with a dense microstructure have been prepared using a spark plasma sintering (SPS) technique. The effects of Bi compensation on its microstructure, crystalline structure, defect chemistry and electrical properties were, then, systematically investigated. The results from the XRD and SEM characterizations revealed that the symmetry of all samples was indexed as rhombohedral-pseudocubic. Also, the defect concentration did first decrease, and then increase, with an increasing x con-tent. In addition, a broad anomaly was observed for the temperature-dependent dielectric constant. A high activation energy and enhanced the temperature of maximum dielectric permittivity (Tm = 382 degrees C at 1 kHz) were observed in the ceramic materials with appropriate Bi compensation (x = 0.005), leading to an enhanced ferroelectricity with a value of Pr & AP;26.7 & mu;C/cm2. The present work has demonstrated that the SPS process, in addition to an adequate Bi compensation, can serve as a promising method for the fabrication of high-performance BaTiO3-BiFeO3-based ceramics.