摘要
A new polar intermetallic compound, Eu3Sn5, has been synthesized by solid-state reaction of the corresponding pure elements in a stoicbiometric ratio in a welded tantalum tube at high temperature. Its crystal structure was established by single-crystal X-ray diffraction. EuaSn5 crystallizes in orthorhombic, space group Cmcm with a = 10.466（11）, b = 8,445（8）, c = 10.662（12）/k, V = 942.4（17）A^3, Z = 4, Mr = 1049.33, De= 7.396 g/cm^3, ,μ = 32.578 mm^-1, F（000） = 1756, the final R = 0.0236 and wR = 0.0472 for 535 observed reflections with I 〉 2σ（I）. Its structure belongs to the modified Pu3Pd5 type. It is isostructural with SraSn5 and Ba3Sn5, featuring [Sn5] square pyramidal clusters described as “arachno” according to the Wade-Mingos electron counting rules. The europium cations are located at the voids between the square pyramidal clusters. Results of the extended Htickel band structure calculations indicate that Eu3Sn5 is metallic.
A new polar intermetallic compound, Eu3Sn5, has been synthesized by solid-state reaction of the corresponding pure elements in a stoicbiometric ratio in a welded tantalum tube at high temperature. Its crystal structure was established by single-crystal X-ray diffraction. EuaSn5 crystallizes in orthorhombic, space group Cmcm with a = 10.466（11）, b = 8,445（8）, c = 10.662（12）/k, V = 942.4（17）A^3, Z = 4, Mr = 1049.33, De= 7.396 g/cm^3, ,μ = 32.578 mm^-1, F（000） = 1756, the final R = 0.0236 and wR = 0.0472 for 535 observed reflections with I 〉 2σ（I）. Its structure belongs to the modified Pu3Pd5 type. It is isostructural with SraSn5 and Ba3Sn5, featuring [Sn5] square pyramidal clusters described as “arachno” according to the Wade-Mingos electron counting rules. The europium cations are located at the voids between the square pyramidal clusters. Results of the extended Htickel band structure calculations indicate that Eu3Sn5 is metallic.
基金
National Natural Science Foundation of China (Nos. 20573113 and 20521101)
NSF of Fujian Province (No. E0420003)
