High remnant polarization in (Sr0.7Bi0.2)TiO3-(Na0.5Bi0.5)TiO3 solid solutions

The dielectric and ferroelectric properties of (1-z) (Sr0.7Bi0.2)TiO3-z(Na0.5Bi0.5)TiO3 solid solutions with z=0.65-1 are studied. High remnant polarization of similar to 51 mu C/cm(2) with a coercive field of 50 kV/cm, and a dielectric constant of similar to 1000 have been obtained at room temperature in the sample with z=0.9, indicating an application potential as a lead-free ferroelectric material. There are two dielectric anomalies in the temperature range of 150-670 K for all samples; one is the dielectric peak without significant frequency dispersion, and the other is significantly frequency dependent. The result of this work shows that the formula scheme "a ferroelectric relaxor+a ferroelectric" for solid solutions is a promising approach in the search for high performance lead-free ferroelectric materials. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3271180]