Rietveld方法研究Bi_(1-x)Sm_xFeO_3晶体结构

Rietveld refinement of Bi_(1-x)Sm_xFeO_3 crystal structure

采用溶胶-凝胶法成功制备Bi1-xSmxFeO3（BSFOx，x=0．000～0．175）粉体．测得BSFOx（x=0．000—0．175）样品的X射线衍射谱（XRD）．XRD结果显示Sm掺杂引起了晶格常数变化并最终导致结构相变．XRD的Rietveld全谱拟合结果表明x=0．000—0．125的BSFO，样品为三角相结构，且随着掺杂含量Sm的增加，晶格常数a、c线性减小；Sm掺杂量增加到x=0．150时，样品转变为正交相结构．

Bi1-xSmxFeO3 （ BSFOx ,x = 0.000 - 0. 175 ） powders were prepared by sol-gol process. X-ray diffraction （XRD） patterns of the BSFOx （x =0. 000-0. 175） samples showed that the Sm doping causes lattice constant change as well as the structure transition. Rietveld refinement of the XRD patterns demonstrated that crystal structure of the BSFOx samples with x = 0.000 - 0. 125 was trigonal structure and lattice constant a, c decreased linearly with the increase of Sm concentration. When the Sm concentration increased to 0. 150, BSFOx structure transformed from trigonal into the orthorhombic.