双钙钛矿型氧化物(Sr_(2-3x)La_(2x)Ca_x)FeMoO_6的电输运性质

Electrical transport properties in(Sr_(2-3x)La_(2x)Ca_x)FeMoO_6 double-perovskites

分别用固相烧结法和溶胶-凝胶法制备了A位双掺杂的双钙钛矿型氧化物(Sr2-3xLa2xCax)Fe-MoO6。XRD显示所有样品均为多晶单相,随掺杂量增加,样品空间群在x=0.2处转变,由I4/m群转变为Fm3-m群。四探针法对电输运性质的表征表明,样品电阻率随反位缺陷程度的加剧而增加,随平均晶粒尺寸的增大而减小,定量掺杂以限制化合物相结构、完善制备工艺以优化晶界条件,能有效控制材料的电导性质。

（Sr2-3xLa2xCax）FeMoO6granules with double perovskite structure have been fabricated by solid sintering technology and sol-gel processes respectively,and were characterized by X-ray diffraction（XRD）and fourprobe meter.XRD spectrums showed the samples preferable phase,with the doping content xincrease the space group changed from I4/m to Fm3-m at x=0.2.The electrical resistivity display different transport behaviors.Optimizing antisite defect and the grain size can effectively change the electrical transport properties in double perovskites structure composites.