State Key Laboratory of Crystal Materials, Institute of Crystal Materials, Shandong University, Jinan, Shandong 250100, People's Republic of China.
Inorg Chem. 2012 May 21;51(10):5771-8. doi: 10.1021/ic300308w. Epub 2012 May 7.
Two new ternary Zintl phases, Sr(5)Sn(2)As(6) and Eu(5)Sn(2)As(6), have been synthesized, and their structures have been accurately determined through single-crystal X-ray diffraction. Both compounds crystallize in orthorhombic space group Pbam (No. 55, Z = 2) with cell parameters of a = 12.482(3)/12.281(5) Å, b = 14.137(3)/13.941(5) Å, and c = 4.2440(10)/4.2029(16) Å for Sr(5)Sn(2)As(6) (R1 = 0.0341; wR2 = 0.0628) and Eu(5)Sn(2)As(6) (R1 = 0.0324; wR2 = 0.0766), respectively. Their structure belongs to the Sr(5)Sn(2)P(6) type, which can be closely related to the Ca(5)Ga(2)As(6) type. Electronic band structure calculations based on the density functional theory reveal an interesting electronic effect in the structure formation of these two types of Zintl phases, which substantially affect their corresponding electronic band structure. Related studies on the thermal stability, magnetism, and thermoelectric properties of Eu(5)Sn(2)As(6) are presented as well.
两种新的三元 Zintl 相 Sr(5)Sn(2)As(6)和 Eu(5)Sn(2)As(6)已被合成，并通过单晶 X 射线衍射准确确定了它们的结构。这两种化合物均为正交晶系 Pbam（No. 55，Z=2）空间群，晶胞参数分别为 a = 12.482(3)/12.281(5) Å，b = 14.137(3)/13.941(5) Å，c = 4.2440(10)/4.2029(16) Å，对于 Sr(5)Sn(2)As(6)（R1 = 0.0341；wR2 = 0.0628）和 Eu(5)Sn(2)As(6)（R1 = 0.0324；wR2 = 0.0766）。它们的结构属于 Sr(5)Sn(2)P(6)类型，可以与 Ca(5)Ga(2)As(6)类型密切相关。基于密度泛函理论的电子能带结构计算揭示了这两种 Zintl 相结构形成中的一个有趣的电子效应，这对它们相应的电子能带结构有很大影响。同时还介绍了 Eu(5)Sn(2)As(6)的热稳定性、磁性和热电性能的相关研究。
