Structure and Ferroelectric Properties of (Bi0.5Na0.5)0.9Ba0.07Sr0.03TiO3 Ceramics by Mn Doping

The effect of a small amount of MnO2 doping on the structure and ferroelectric properties of (Bi0.5Na0.5)(0.9)Ba0.07Sr0.03TiO3 (BNBST)ceramics prepared by the conventional mixed oxide method was systematically investigated. X-Ray diffraction shows that all ceramics samples have a pure perovskite structure and a morphotropic phase boundary between tetragonal and rhombohedral phase locates in the range of 0.20 < x < 0.75. At x = 0.25, the MnO2-modified BNBST ceramics exhibit excellent ferroelectric properties composed by a higher remanent polarization P-r (P-r=25.9 mu C/cm(2)) and lower coercive field E-C (E-C=2.54 kV/mm) at room temperature. Moreover, the two characteristic dielectric peaks can be observed in this ceramics.