Synthesis, magnetic and electrical transport properties of magnetoresistance material Sr<sub>2sub>FeMoO<sub>6sub> by microwave sintering
- 作者：Yongqing Zhai<sup> ; sup><sup>zhaiyongqinghbu@163.comsup> ; Jing Qiao ; Guoyan Huo ; Shaoqiang Han
- 关键词：Microwave synthesis ; Sr2FeMoO6 ; Magnetic and electrical transport properties ; Magnetoresistance
- 刊名：Journal of Magnetism and Magnetic Materials
- 出版年：2012
- 期刊代码：31_03048853
- 类别：ph
- 出版时间：July, 2012
- 卷：324
- 期：13
- 页码：2006-2010
- 文件大小：410 K
摘要
Magnetoresistance material Sr<sub>2sub>FeMoO<sub>6sub> with double perovskite structure was synthesized by microwave sintering method using SrCO<sub>3sub>, Fe<sub>2sub>O<sub>3sub> and MoO<sub>3sub> as raw materials, with MnO<sub>2sub> for microwave absorber. The phase structure, magnetic and electrical transport properties were investigated by X-ray powder diffraction (XRD) and vibrating-sample magnetometer. XRD analysis shows that the as-synthesized sample is Sr<sub>2sub>FeMoO<sub>6sub> with tetragonal crystal structure and I4/mmm space group. The unit cell parameters are a=0.5587 nm, c=0.7894 nm, volume=0.2464 nm<sup>3sup>. The calculated grain size of the sample is 31.62 nm, which is obtained by the Scherrer formula using the diffraction data. Magnetism testing results show that the sample Sr<sub>2sub>FeMoO<sub>6sub> is ferromagnetic with the magnetic transition temperature of about 380 K. Under 1.0 T magnetic field, the saturation and spontaneous magnetization of Sr<sub>2sub>FeMoO<sub>6sub> is 1.25 渭<sub>Bsub>/f.u. and 1.00 渭<sub>Bsub>/f.u. at room temperature. The magnetoresistance ratio of the sample is 28%. Electrical transport properties testing results indicate that the sample exhibits typical semiconductor behavior. The conductive mechanism of Sr<sub>2sub>FeMoO<sub>6sub> is highly dependent on temperature: within the temperature range of 100-300 K, the mechanism is attributed to the small polaron variable-range hopping model; while it is ascribed to the adiabatic small polaron model within the temperature range of 80-100 K.