溶胶-凝胶法制备双钙钛矿型氧化物SrLaMnBO_6(B:Mo,W)及其磁学性能  

Preparation and Magnetic Properties of Double Perovskites SrLaMnBO_6(B:Mo,W) by Sol-Gel Route

作　　者：田世哲[1] 赵军钗[1] 乔从德[1] 姬相玲[1] 姜炳政[1] 

机构地区：[1]中国科学院长春应用化学研究所高分子化学与物理国家重点实验室,长春130022

出　　处：《应用化学》2006年第9期945-948,共4页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金资助项目(90101001);中国科学院方向性项目(KJCX2-SW-H07);"九七三"项目(G1999064800);吉林省杰出青年基金(20050104);吉林省科技厅和长春市科技局国际合作项目(20050702-2;04-03GH268)

摘　　要：通过溶胶-凝胶方法,制得了单相SrLaMnMoO6和SrLaMnWO6有序双钙钛矿多晶样品。X射线衍射结果表明,SrLaMnMoO6为单斜晶系,SrLaMnWO6属四方晶系结构,并且由于电子因素和结构因素的竞争导致掺杂后样品晶胞体积增大。磁性测量显示,二者都呈现很弱的铁磁性,外推得到的磁矩分别为0.72μB和0.16μB,远小于理论预测结果。SrLaMnMoO6的热磁曲线可观察到铁磁-顺磁转变,而SrLaMnWO6的热磁曲线则未观察到这种转变。The ordered double perovskites SrLaMnBO6 （B：Mo, W） were prepared by sol-gel reaction. The XRD results suggest that the crystal structure of SrLaMnMoO6 belongs to the monoclinic P2 1/n space group and that of SrLaMnWO6 belongs to the tetragonal I4/m space group. The competition between band filling effect and steric effect results in the expansion of cell volume for SrLaMnBO6 （B：Mo, W）. Magnetic measurements indicated that both samples showed very weak ferro-/ferrimagntism, but the magnetic moments at H = 0 extrapolated from the magnetic moment vs applied magnetic field curves are 0. 721μB and 0. 16μB for SrLaMnMoO6 and SrLaMnWO6, respectively, much smaller than the expected net magnetic moments. From the temperature dependence of magnetization for SrLaMnMoO6, ferromagnetic-paramagnetic transition is observed, which is not shown for SrLaMnWO6.

关 键 词：双钙钛矿型 溶胶-凝胶 掺杂 晶胞参数 磁性 

分 类 号：O611.6[理学—无机化学] O482.5[理学—化学]