Pd₅InSe and Pd₈In₂Se - New metal-rich homological selenides with 2D palladium-indium fragments: Synthesis, structure and bonding

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• 作者：Elena Yu. Zakharova ; Sergey M. Kazakov ; Anna A. Isaeva ; Artem M. Abakumov ; Gustaaf Van Tendeloo ; Alexey N. Kuznetsov
• 关键词：Intermetallics ; Transition metal alloys and compounds ; Crystal structure ; Electronic band structure ; Transmission electron microscopy ; TEM ; X-ray diffraction
• 刊名：Journal of Alloys and Compounds
• 出版年：15 March, 2014
• 年：2014
• 卷：589
• 期：Complete
• 页码：48-55
• 全文大小：2614 K

文摘

Two new metal-rich palladium-indium selenides, Pd₅InSe and Pd₈In₂Se, were synthesized using a high-temperature ampoule technique. Their crystal structures were determined from Rietveld analysis of powder diffraction data, supported by energy-dispersive X-ray spectroscopy and selected area electron diffraction. Both compounds crystallize in tetragonal system with P4/mmm space group (Pd₅InSe: a = 4.0290(3) 脜, c = 6.9858(5) 脜, Z = 1; Pd₈In₂Se: a = 4.0045(4) 脜, c = 10.952(1) 脜, Z = 1). The first compound belongs to the Pd₅TlAs structure type, while the second one - to a new structure type. Main structural units in both selenides are indium-centered [Pd₁₂In] cuboctahedra of the tetragonally distorted Cu₃Au type, single- and double-stacked along the c axis in Pd₅InSe and Pd₈In₂Se, respectively, alternating with [Pd₈Se] rectangular prisms. DFT electronic structure calculations predict both compounds to be 3D metallic conductors and Pauli-like paramagnets. According to the bonding analysis based on the electron localization function topology, both compounds feature multi-centered palladium-indium interactions in their heterometallic fragments.