掺杂对PMN-10PT铁电陶瓷介电性能的影响

Effects of Doping on Dielectric Properties of PMN-IOPT Ceramics

铌镁酸铅与钛酸铅组成比为9:1(PMN-10PT)的固溶体陶瓷是典型的弛豫铁电体,其介电行为与偶极玻璃的介电行为极为相似.本文使用常用的Swartz两步法,研究了基体掺杂不同物质对PMN-10PT铁电陶瓷的介电性能的影响.经研究发现,当掺入Li2O时,材料的峰值介电常数为28640,大于纯PMN-10PT,而频率色散和弥散相变的程度都变小.当掺杂CaO和Yb2O3时,材料的峰值介电常数下降,分别为19300和18850,它们的频率色散和弥散相变的程度都变大了.同时通过拉曼光谱研究了PMN-10PT陶瓷的B位离子有序度的变化.

PMN-10PT is a kind of well-known typical relaxor ferroelectrics, whose dielectrical behavior is analogous to that of spin-glass systems. Dielectric properties were studied by adding a small amount of different dopants into PMN-lOPT ceramics using the normal two-step method. When doped with Li2O, the maximum dielectric constant of this material is 28640, which is higher than that of pure PMN-lOPT, while the degree of frequency dispersion and DPT are decreased. When doped with CaO and Yb2O3, on the contrary, the opposite results will be obtained. In addition, the Raman spectra show that the degree of B-site order of the materials is increased when doped with Li2O and decreased when doped with Yb2O3, respectively.