中国物理B ›› 2012, Vol. 21 ›› Issue (4): 46501-046501.doi: 10.1088/1674-1056/21/4/046501

• • 上一篇    下一篇

李求杰,袁保合,宋文博,梁二军,袁斌   

  • 收稿日期:2011-06-05 修回日期:2011-12-24 出版日期:2012-02-29 发布日期:2012-02-29
  • 通讯作者: 梁二军,ejliang@zzu.edu.cn E-mail:ejliang@zzu.edu.cn

The phase transition, hygroscopicity, and thermal expansion properties of Yb2-xAlxMo3O12

Li Qiu-Jie(李求杰), Yuan Bao-He(袁保合), Song Wen-Bo(宋文博), Liang Er-Jun(梁二军), and Yuan Bin(袁斌)   

  1. School of Physical Science & Engineering and Key Laboratory of Materials Physics of Ministry of Education of China, Zhenghou University, Zhengzhou 450052, China
  • Received:2011-06-05 Revised:2011-12-24 Online:2012-02-29 Published:2012-02-29
  • Contact: Liang Er-Jun,ejliang@zzu.edu.cn E-mail:ejliang@zzu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 10974183).

Abstract: Materials with the formula Yb2-xAlxMo3O12 (x=0.1, 0.2, 0.3, 0.4, 0.5, 0.7, 0.9, 1.0, 1.1, 1.3, 1.5, and 1.8) were synthesized and their structures, phase transitions, and hygroscopicity investigated using X-ray powder diffraction, Raman spectroscopy, and thermal analysis. It is shown that Yb2-xAlxMo3O12 solid solutions crystallize in a single monoclinic phase for 1.7≤ x≤ 2.0 and in a single orthorhombic phase for $0.1\le x\le 0.4$, and exhibit the characteristics of both monoclinic and orthorhombic structures outside these compositional ranges. The monoclinic to orthorhombic phase transition temperature of Al2Mo3O12 can be reduced by partial substitution of Al3+ by Yb3+, and the Yb2-xAlxMo3O12 (0.0< x≤ 2.0) materials are hydrated at room temperature and contain two kinds of water species. One of these interacts strongly with and hinders the motions of the polyhedra, while the other does not. The partial substitution of Al3+ for Yb3+ in Yb2Mo3O12 decreases its hygroscopicity, and the linear thermal expansion coefficients after complete removal of water species are measured to be -9.1× 10-6/K, -5.5× 10-6/K, 5.74× 10-6/K, and -9.5× 10-6/K for Yb1.8Al0.2(MoO4)3, Yb1.6Al0.4(MoO4)3, Yb0.4Al1.6(MoO4)3, and Yb0.2Al1.8(MoO4)3, respectively.

Key words: negative thermal expansion material, phase transition, hygrosopicity, Raman spectroscopy

中图分类号:  (Thermal expansion; thermomechanical effects)

  • 65.40.De
61.50.Ks (Crystallographic aspects of phase transformations; pressure effects) 82.30.Rs (Hydrogen bonding, hydrophilic effects) 78.30.-j (Infrared and Raman spectra)