激光辐照对PZT-4陶瓷介电性能的影响

Effect of Laser Irradiation on Dielectric Properties of PZT-4 Ceramic

研究了CO2激光辐照对PZT-4陶瓷介电性能的影响。在一定的激光辐照功率密度下,PZT-4陶瓷的介电常数下降约5%,介电损耗下降约60%,矫顽场增加。结合拉曼光谱、扫描电子显微镜、X射线衍射以及后退火处理探讨了激光辐照PZT-4陶瓷的改性机理,结果表明,激光辐照后陶瓷介电性能的变化主要与其微结构有关,辐照使得陶瓷产生了较大的张应力,晶格常数变大,B位离子更容易偏离氧八面体中心,氧八面体扭曲,使其电畴活性下降,阻碍了极化翻转,材料性能变"硬"。

The effect of CO2 laser irradiation on the dielectric properties of PZT-4 ceramic is investigated.After laser irradiation,dielectric permittivity and dielectric loss of the ceramic decrease 5% and 60%,respectively,and the coercivity increases.The mechanism of the changes are analysed by Raman scattering,scanning electron microscope（SEM）,X-ray diffraction（XRD） and the annealing process.It is shown that the microstructure changes of the irradiated sample mainly account for the dielectric properties.The CO2 laser irradiation could induce the tension stress,leading to the larger lattice parameter and the deviation of B site ion from the center of oxygen octahedron.The distortion of the oxygen octahedron results in the less activation of electric domains.Therefore,the polarization switching of the electric domains become more difficult,exhibiting the properties of ＂hard＂.This suggests that the laser irradiation may offer a new approach for the fabrication of lead zirconate titanate（PZT） based ＂hard martial＂ in several seconds without any ions addition.