Synthesis of new fluorite-related rare earth oxides Ln lns:search="http://marklogic.com/appservices/search">\({\text{Ln}}_{2}^{\prime }\) MO₇ (Ln, Ln′ = rare earths; M = Nb, Sb, Ta), their structu

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• 作者：Yukio Hinatsu ; Yoshihiro Doi
• 关键词：Specific heat ; Magnetic properties ; Rare earth ; Niobium ; Oxide
• 刊名：Journal of Thermal Analysis and Calorimetry
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：127
• 期：1
• 页码：749-754
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Physical Chemistry; Analytical Chemistry; Polymer Sciences; Inorganic Chemistry; Measurement Science and Instrumentation;
• 出版者：Springer Netherlands
• ISSN：1588-2926
• 卷排序：127

文摘

New fluorite-related quaternary rare earth oxides Ln\({\text{Ln}}_{2}^{\prime }\)MO₇ (Ln = Nd, Gd, Tb; Ln′ = Lu and Y; M = Nb, Sb, Ta) were prepared. They crystallize in an orthorhombic superstructure of cubic fluorite with space group C222₁. The results of the Rietveld analysis indicate that there exists some disordering of the Ln and Ln′ atoms at the eight-coordinate site and the seven-coordinate site. These compounds are paramagnetic down to 1.8 K except for TbLu₂SbO₇. Magnetic susceptibility measurements show that TbLu₂SbO₇ antiferromagnetically orders at 3.0 K. Specific heat measurements also show a λ-type anomaly at the same temperature. The analysis of the magnetic specific heat for TbLu₂SbO₇ indicates that the magnetic transitions are due to the ground doublet state of Tb3+ ions.