【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。更多还原

【Abstract】 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 P2₁/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 0.72μ_B and 0.16μ_B 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.更多还原