ChemInform Abstract: LiPbSb₃S₆: A Semiconducting Sulfosalt with Very Low Thermal Conductivity.

Abstract

LiPbSb 3 S 6 : A Semiconducting Sulfosalt with Very Low Thermal Conductivity. -LiPbSb3S6 is prepared by stoichiometric solid state reaction of Li2S, Pb, Sb, and S (evacuated carbon-coated silica ampule, 800°C, 2 h, quenching; 98% yield). The new compound crystallizes as a member of the lillianite homologous series and is composed of PbS-type Sb/Li-S layers separated by trigonal-prismatic-coordinated Pb/Li (monoclinic, space group P2 1 /c, Z = 4, powder XRD). Electronic band structure calculations indicate an indirect band gap with direct gaps lying very close in energy. LiPbSb3S6 has a thermal conductivity of 0.24 W/m·K at room temperature, one of the lowest thermal conductivities ever seen in a crystalline material, together with a high resistivity of 4·10 9 Ωcm and strong light absorption with a nearly direct band gap of 1.6 eV. -(AGHA, E. C.; MALLIAKAS, C. D.; IM, J.; JIN, H.; ZHAO, L.-D.; FREEMAN, A. J.; KANATZIDIS*, M. G.; Inorg. Chem. 53 (2014) 2, 673-675, http://dx.doi.org/10.1021/ic402262z ; Dep. Chem., Northwest. Univ., Evanston, IL 60208, USA; Eng.) -J. Schramke 12-015