Experimental and theoretical studies of Sn 3− δ Pb δ Bi 2Se 6 ( δ=0.0–0.7)

• Published in: Journal of solid state chemistry Vol. 183; no. 4; pp. 807 - 813
• Main Authors: Chen, Kuei-Bo, Lee, Chi-Shen
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 2010
• Subjects: Antimony; Bismuth; Chalcogenide; Lead; Quaternary; Selenide; Tin; Chalcogenide; Selenide; Quaternary; Tin; Lead; Bismuth; Antimony
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2010.01.011

New ternary and quaternary chalcogenides, Sn 3− δ Pb δ Bi 2Se 6 ( δ=0.0–0.7), were synthesized from pure elements using the solid-state method. Their crystal structures, determined using single crystal X-ray diffraction, belong to the orthorhombic space group Pnma (No. 62). The structure is related to Pb 3Bi 2S 6, which contains NaCl [311] layer units and zigzag arrays of metal atoms along the c-axis. A correlation between the Pb composition and the shifted position of a metal site was observed. Band structure calculations confirmed that the structure is stabilized when the position of the M5 site is farther from the mirror plane. Thermopower and conductivity measurements indicated that all of the compounds are n-type semiconductors with small band gaps. New ternary and quaternary chalcogenides, Sn 3− δ Pb δ Bi 2Se 6 ( δ=0.0–0.7), were synthesized and their structures are related to that of Pb 3Bi 2S 6 with an atomic position near the cell-twinning plane. Band structure calculations confirmed that the structure is stabilized when the position of the M5 site is farther from the cell-twinning plane. All compounds are n-type semiconductors with small band gaps.