Effects of doping Fe cations on crystal structure and thermal expansion property of Yb2Mo3O12

Research paper by Ying-Zhi Cheng, Xiu-Yu Sun, Xiao-Ling Xiao, Xiang-Feng Liu, Li Xue, Zhong-Bo Hu

Indexed on: 22 Mar '17Published on: 04 Mar '17Published in: Chinese Chemical Letters


Crystal structures and thermal expansion properties of Yb2−xFexMo3O12 (x = 0.0, 0.6, 1.0, 1.1, 1.4) solid solutions have been studied by X-ray powder diffraction (XRPD) at different temperatures. Rietveld analysis of the XRPD data shows that Yb2−xFexMo3O12 solid solutions adopt orthorhombic structure and have variable thermal expansion coefficients controlled by the ratio of Yb3+ to Fe3+. Yb2Mo3O12 shows anisotropic negative thermal expansion property, induced by the reductions in average Yb–O–Mo angle and average apparent Mo2–O bond length with increasing temperatures. As more Yb3+ substituted by Fe3+, the linear thermal expansion coefficients of Yb2−xFexMo3O12 increase from negative to positive. A near-zero thermal expansion coefficient of 0.55 × 10−6 K−1 for Yb0.6Fe1.4Mo3O12 is observed in the temperature range of 573–873 K

Graphical abstract 10.1016/j.cclet.2017.03.002.jpg