中国物理B ›› 2012, Vol. 21 ›› Issue (6): 66102-066102.doi: 10.1088/1674-1056/21/6/066102
• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇 下一篇
高庆庆, 李静波, 宋士佳, 骆军, 饶光辉, 梁敬魁
Gao Qing-Qing(高庆庆), Li Jing-Bo(李静波)†, Song Shi-Jia(宋士佳), Rao Guang-Hui(饶光辉), Luo Jun(骆军), Liu GuangYao(刘广耀), and Liang Jing-Kui(梁敬魁)‡
摘要: New oxometallides with the formula Ba5Y8-xMn4O21-1.5x (x=0, 1) are prepared through an atmosphere-controlled solid-state reaction. Two single-phase samples with Ba/Y/Mn atomic ratios 5/8/4 (Y8) and 5/7/4 (Y7) are obtained. The crystal structures and the physical properties of the compounds are investigated by X-ray powder diffraction, magnetization, conductivity, and dielectricity measurements. The Ba5Y8-xMn4O21-1.5x compound is demonstrated to be a Y-deficient solid solution. The solid solution compound Ba5Y8-xMn4O21-1.5x crystallizes into tetragonal symmetry with the space group I4/m. Detailed structure analysis by Rietveld refinement of the X-ray powder diffraction data reveals that the Y vacancies occur preferentially at the Y(2) site. Thermal magnetization measurements indicate the presence of antiferromagnetic interaction between Mn ions in the compounds, and temperature-dependent resistivity measurements show that insulator-semiconductor transitions occur around 175 K and 170 K for the Y8 and Y7 samples, respectively. Strong frequency dependences of the dielectric constant are observed above ~ 175 K for the two compounds.
中图分类号: (X-ray diffraction)