The crystal structures and physical properties of the solid solution compound Ba5Y8-xMn4021-1.5x （x = 0, 1）

• Published in: 中国物理B：英文版 2012, Vol.21 (6), p.364-369
• Main Author: 高庆庆 李静波 宋士佳 饶光辉 骆军 刘广耀 梁敬魁 赵孟珂 梁艳 郜小勇 陈超 陈先梅 赵显伟
• Format: Article
• Language: English
• Subjects: Rietveld精修; X-射线粉末衍射; 化合物; 固溶体; 晶体结构; 物理性质; 磁化强度; 粉末衍射数据
• ISSN: 1674-1056; 2058-3834

New oxometallides with the formula Ba5Y8-xMn4021-1.5x （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-xMn4021-1.5x compound is demonstrated to be a Y-deficient solid solution. The solid solution compound Ba5Y8-xMn4021-1.5x 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.