Gd掺杂对0.7BiFeO_3-0.3BaTiO_3固溶体的结构和性能的影响

Effects of Gd-Doping on Microstructure and Properties of 0.7BiFeO3-0.3BaTiO_3 Solid Solutions

采用固相法合成了0.7BiFeO3-0.3BaTiO3-xmolGd2O3固溶体(x=0,0.003,0.006,0.009,0.012).XRD测试结果显示:0.7BiFeO3-0.3BaTiO3在室温下是赝立方相,Gd2O3的掺入抑制了四方相的形成,随着Gd3+掺入量的增加,样品结构从赝立方相向三方相转变.介电性能测试表明:较高频率下,相对于其它样品,掺杂量为0.009和0.012的样品的介电性能明显提高;介电损耗随掺杂量增加明显增大.同时相关测试结果显示:Gd掺杂使样品的介温曲线变平缓,尤以掺杂量为0.009样品最为明显,其介电损耗曲线变化亦较缓慢,表明该样品介电性能的稳定性有较大提高.

The solid solutions of 0.7BiFeO3-0.3BaTiO3-xmolGd2O3 with x= 0, 0. 003, 0. 006, 0. 009 and 0. 012 have been prepared via solid-state reaction. XRD and Agilent 4294A Impedance Analyzer are used to measure the microstructure and dielectric properties of the samples. The sample 0.7BiFeO3-0.3BaTiO3 is pseudo-cubic at room temperature, and the introduction of Gd2O3 restrains the formation of tetragonal. With the increase of the Gd^3＋ content, the structure of the samples changes into trigonal. Compared with other samples, the dielectric properties of samples with x = 0. 009 and 0. 012 are improved remarkably at higher frequencies while the loss tangent is higher than the un-doped 0. 7BiFeO3-0.3BaTiO3 ceramics. Gd-doping has improved the stability of the dielectric property. For the sample with x = 0. 009, the stability of the dielectric property is improved remarkably.