半化学法制备工艺对PMN-PT陶瓷电性能的影响

以硝酸镁代替MgO,采用两种半化学法制备工艺分别制备了铌镁酸铅-钛酸铅陶瓷,并研究了陶瓷的相组成、显微结构和电性能。实验结果表明,采用两步半化学法(SCM-A)制备的陶瓷为纯钙钛矿相结构,晶粒大小约为5μm,结构致密,该陶瓷的介电常数峰值达45 000,剩余极化强度为31.8μC/cm2,压电常数为450 pC/N;而采用一步半化学法(SCM-B)制备的陶瓷则含有少量焦绿石相,晶粒大小约为2μm,该陶瓷的介电常数峰值为25 000,剩余极化强度约为26.9μC/cm2,压电常数为360 pC/N。

Effect of Preparation Technics of Semichemical Method on Electric Properties of PMN-PT Ceramics

Using MgNO_3·6H_2O instead of MgO as raw material,the lead magnesium niobate—lead titanate ceramics were prepared by two type preparation technics of semichemical method.Moreover,the phase composition,microstructure and electric properties of these ceramics were researched.The experimental results showed that pure perovskite phase structure,large grain size(about 5 μm) and dense microstructure were obtained in the ceramic prepared by two step semichemical method(SCM-A).For this ceramic,the maximum value of dielectric constant reaches(45 000),the remnant polarization is 31.8 μC/cm~2,and piezoelectric constant is 450 pC/N.However,a little pyrochlore phase and fine grain(about 2 μm) was observed in the ceramic prepared by one-step semichemical method(SCM-B).For this ceramic,the maximum value of dielectric constant is(25 000),the remnant polarization is 26.9 μC/cm~2,and piezoelectric constant is 360 pC/N.