摘要
以无机盐为前驱体,利用溶胶-凝胶法固溶合成了(1-x)Pb(Fe2/3W1/3)O3-xPb(Mg1/2W1/2)O3多铁性固溶体.XRD分析表明,在0≤x≤1.0的掺杂范围内,700℃煅烧所得产物都具有钙钛矿结构;x=0时得到的纯Pb(Fe2/3W1/3)O3为长程无序结构,x=1.0时可获得完全有序的纯Pb(Mg1/2W1/2)O3相,其单胞为Pb(Fe2/3W1/3)O3单胞的2倍;当0<x<1.0时,(1-x)Pb(Fe2/3W1/3)O3-xPb(Mg1/2W1/2)O3固溶体也为有序结构,出现1/2(111)及1/2(311)XRD衍射峰,且强度随掺杂系数x的升高逐渐增大.TEM分析证实,煅烧产物为具有钙钛矿结构的单相固溶体,而非两相复合物;固溶相形貌以立方颗粒为主,随掺杂量增加其晶胞常数线性增大,而晶粒尺寸先减小后变大.性能测试发现,固溶相的磁学性能随x的增加而逐渐下降,起因于抗磁性的Pb(Mg1/2W1/2)O3破坏了Pb(Fe2/3W1/3)O3原有的价键结构所致.
Pb（Fe2/3W1/3）O3 was modified by doping Pb（Mg1/2W1/2）O3 with Sol-Gel method using inorganic salts as precursors.At calcination temperature of 700℃,the resulted solid solution（1-x）Pb（Fe2/3W1/3）O3-xPb（Mg1/2W1/2）O3 kept a perovskite structure in the whole doping range of 0≤x≤1.The obtained Pb（Mg1/2W1/2）O3（x=1） is fully or-dered with a unit cell as two times as that of Pb（Fe2/3W1/3）O3（x=0）.Solid solution（1-x）Pb（Fe2/3W1/3）O3-xPb（Mg1/2W1/2）O3（0x1.0） also has an ordered crystal structure showing supperlattice peaks of 1/2（111） and 1/2（311） in X-ray diffraction,whose intensities become stronger as x increases.Combining electron diffraction and elemental analysis in transmission electron microscope,solid solution（1-x）Pb（Fe2/3W1/3）O3-xPb（Mg1/2W1/2）O3 is verified as a single phase with perovskite structure,rather than a mixture of two phases.The particles of solid solu-tion have a cubic morphology,and their grain size first decreases and then increases when doping coefficient x var-ies from 0.2 to 0.8.Due to the substitution of larger Mg2＋ for smaller Fe3＋ ions,its lattice constant increases linearly with the enhancement of x.According to the measured M-H curves,the magnetic performance of the solid solution decays as the doping coefficient x increases,because the formation of diamagnetic Pb（Mg1/2W1/2）O3 could destroy the -Fe3＋-W-O-W-Fe3＋- and -Fe3＋-O-Fe3＋- magnetic bonds in antiferromagnetic Pb（Fe2/3W1/3）O3 phase.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第6期649-654,共6页
Journal of Inorganic Materials
基金
国家重点基础研究发展计划973项目(2010CB631006)
中国科学院百人计划项目~~
