Synthesis and Theoretical Investigations of the Solid Solution CeRu1鈥?i>xNixAl (x = 0.1鈥?.95) Showing Cerium Valence Fluctuations

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• 作者：Oliver Niehaus ; Ute Ch. Rodewald ; Paula M. Abdala ; Rachid St. Touzani ; Boniface P. T. Fokwa ; Oliver Janka
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：March 3, 2014
• 年：2014
• 卷：53
• 期：5
• 页码：2471-2480
• 全文大小：469K
• 年卷期：v.53,no.5(March 3, 2014)
• ISSN：1520-510X

文摘

Members of the solid solution series of CeRu_1鈥?i>xNi_xAl can be obtained directly by arc melting of the elements. The presented compounds with 0.1 鈮?x 鈮?0.85 crystallize in the orthorhombic space group Pnma (No. 62) in the LaNiAl structure type, while for 0.9 鈮?x 鈮?1, the hexagonal ZrNiAl-type structure is found. The orthorhombic members exhibit an anomaly in the trend of the lattice parameters as well as an interesting behavior of the magnetic susceptibility, suggesting that the cerium cations exhibit no local moment. Besides the mixed-valent nature of the cerium cations, valence fluctuations along with a change in the cerium oxidation state depending on the nickel content have been found. The oxidation state has been determined from the magnetic data and additionally by XANES. Density functional theory calculations have identified the shortest Ce鈥揜u interaction as decisive for the stability of the orthorhombic solid solution.