2006

StructureD 2000 Sphalerite—Chalcopyrite Polymorphism in Semimetallic ZnSnSb2. — The title

compound is synthesized from mixtures of Zn, Sb, and excess Sn which acts as a reactive flux (250—350 °C, 48 h). The samples are characterized by powder XRD, EDX, SEM, and frozen core all-electron projected augmented wave calculations. The material shows an order—disorder transition in the temperature interval 225—240 °C. The high-temperature form adopts the Zn/Sn disordered cubic sphalerite-type structure and the low-temperature form the Zn/Sn ordered tetragonal chalcopyrite structure. The tetragonal low-temperature form has a narrow band gap of about 0.2 eV. Although the electronic structure of ZnSnSb2 is qualitatively similar to thermoelectric binary Zn—Sb frameworks, its thermopower is rather low with room temperature values ranging from 10 to 30 µV/K. — (TENGAA, A.; GARCIA-GARCIA, F. J.; MIKHAYLUSHKIN, A. S.; ESPINOSA-ARRONTE, B.; ANDERSSON, M.; HAEUSSERMANN*, U.; Chem. Mater. 17 (2005) 24, 6080-6085; Dep. Inorg. Chem., Arrhenius Lab., Univ. Stockholm, S-106 91 Stockholm, Swed.; Eng.) — W. Pewestorf

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