双钙钛矿Sr2FeMoO6的微波合成、表征及电磁性能

Microwave Synthesis, Characterization, Magnetic and Electrical Properties of Double Perovskite Sr2FeMoO6

摘要:

以SrCO3、Fe2O3、MoO3为原料，MnO2为微波吸收剂，采用微波烧结法成功合成双钙钛矿Sr2FeMoO6粉体。XRD结果表明，产品为四方晶系Sr2FeMoO6，空间群为I4/mmm，晶胞参数为：a = 0.5571 nm，c = 0.7872 nm，利用X射线衍射数据经Scherrer公式计算所得样品的晶粒尺寸为20 nm左右。磁性能测试结果表明，样品表现为铁磁性，磁转变温度高于室温，1 T磁场下室温饱和磁化强度为17.949 (A·m2)/kg。电性能测试结果表明，样品呈现典型的半导体行为，导电机制属于绝热小极化子导电机制，样品在1 T磁场下的室温磁电阻变化率可达–15.63%

Abstract:

With MnO2 as microwave absorbent, double perovskite Sr2FeMoO6 powder was synthesized by microwave processing using SrCO3, Fe2O3 and MoO3 as starting materials. XRD patterns reveal that the as-synthesized product is Sr2FeMoO6 with tetragonal crystal structure and I4/mmm space group, and the unit cell parameter is a =0.5571 nm as well as c = 0.7872 nm. The grain size of the sample is about 20 nm, calculated by the Scherrer formula using the diffraction data. Magnetism testing results show that the sample is ferromagnet, the transition temperature is higher than room temperature and the saturation magnetization is 17.949 (A·m2)/kg under 1 T at room temperature. Electrical performance testing results show that the sample exhibit typical semiconductor behavior and the conductive mechanism can be described by adiabatic small polaron model. The room temperature magnetoresistance of the sample under 1 T field is up to –15.63%