BaTiO_3-Bi(Ni_(2/3)Nb_(1/3))O_3弛豫铁电陶瓷结构、介电与储能性能研究

Microstructure,dielectric and energy storage properties of BaTiO_3-Bi(Ni_(2/3)Nb_(1/3))O_3 relaxor ferroelectric ceramics

采用固相法制备(1-x)BaTiO_3-xBi(Ni_(2/3)Nb_(1/3))O_3(x=3,5,7,10,15,20mol%)(简称BTBNN)弛豫铁电陶瓷,研究了BTBNN陶瓷的结构、介电性能和铁电性能.研究结果表明,Bi(Ni2/3Nb1/3)O3(简称BNN)可以有效降低BaTiO3陶瓷的烧结温度.XRD表明BTBNN陶瓷的晶体结构随BNN含量的增加从四方相转变为伪立方的钙钛矿结构.介电温谱结果表明BTBNN陶瓷表现出弛豫铁电陶瓷的特征,最大介电常数εm随BNN含量增加逐渐减小,而最大介电常数对应的温度Tm呈现先减小后增加的趋势.当x=20mol%时,BTBNN陶瓷获得250kV/cm的击穿电场和2.03J/cm3的可释放能量密度.

（1 -x） BaTiO3 -x Bi （Ni2/3 Nb1/3 ） O3 （x = 3,5,7,10,15,20 mol % ） （BTBNN） relaxor ferroelectric ceramics were synthesized by solid state method. The structure, dielectric properties and ferroelectric properties of BTBNN ceramics were systematically investigated. The results showed that the Bi（Ni2/aNb1/3）O3 （BNN） addition could lower the sintering temperature of BT based ceramics. X ray diffraction results revealed that the crystal structure of BTBNN ceramics changed from tetragonal to pseudo cubic perovskite structure with the increasing BNN content. Dielectric measurements exhibited a relaxor like characteristic for the BTBNN ceramics,where εm decreased with the increasing BNN content,and the T,,, decreased first and then increased with increasing BNN content. The dielectric breakdown strength of 250 kV/cm and a releasable energy density of 2.03 J/cm3 were achieved in the sample of x= 20 mol%.