Bi_(3.15)Nd_(0.85)Ti_3O_(12)陶瓷的铁电介电性能研究

Ferroelectric and dielectric properties of Bi_(3.15)Nd_(0.85)Ti_3O_(12) ceramics

采用传统固相反应法制备了Bi3.15Nd0.85Ti3O12(BNdT)陶瓷.在1 100℃烧结的BNdT陶瓷呈层状钙钛矿结构,致密,晶粒呈扁平状.该陶瓷表现出良好的铁电介电特性,其电滞回线对称,在210 kV/cm测试电场下,剩余极化2Pr和矫顽场Ec分别为45μC/cm2和67.6 kV/cm.在室温f=100 kHz时,εr=221,tgδ=0.006 4.变温介电测试表明居里温度在408℃左右,这一较宽的相变峰,可能是由于氧空位产生的介电弛豫引起的.漏电流测试表明,BNdT陶瓷在低于230 kV/cm电场下,漏电流密度保持在7.5×10-7A/cm2以下,在低于75 kV/cm电场下,该陶瓷呈现肖特基(Schottky)导电行为.

Dense Bi3.15Nd0.85Ti3O12（BNdT） ceramics of a layered perovskite structure were sintered at 1 100 ℃ by solid state reaction. The ceramics consist of plate - shaped grains. The BNdT ceramics exhibit saturated ferroelectric hysteresis loops with a remanent polarization （ 2Pr ） of 45μC/cm^2 and a coercive field of 67.6 kV/cm. The dielectric constant and dissipation factor of the ceramics at 100 kHz are 221 and 0. 0064, respectively. A broad dielectric peak was observed around 408 ℃, and it might come from the oxygen - vacancy - related dielectric relaxation. The leakage current density of the ceramics is less than 7.5 × 10- 7A/cm^2 under an applied field below 230 kV/cm. The BNdT ceramics show Schottky emission behavior under low electric field below 75 kV/cm.