Pressure Stabilized Se-Se Dimer Formation in PbSe2
The preparation of PbSe2 through the reaction of PbSe with excess Se at 4.5 GPa and 650 :deg:C is reported. The crystal structure, determined from X-ray powder diffraction data (CuAl2 structure type, I4/mcm (#140), a = 6.42695(11) , c = 7.70254(13) , Z = 4), consists of layers of [Se2]2- dimers with Pb2+ in square antiprismatic coordination with Se. This is a rare crystal structure for divalent metal chalcogenides, previously only identified for SrS2 and BaTe2. Undoped PbSe2 as well as Bi3+- and Ag+-doped samples (10% Pb substitution) show semi-metallic resistivity down to 0.4 K. Magnetic susceptibility measurement of PbSe2 shows no magnetic ordering above 1.8 K. The Seebeck coefficients show nearly linear behavior from 35 to 400 K and the largest numerical values are found in the case of undoped PbSe2, + 99 μVK-1, and Bi3+-doped PbSe2, - 146 μVK-1, at the highest temperature measured, 400 K.
M. Bremholm et al., "Pressure Stabilized Se-Se Dimer Formation in PbSe2," Solid State Sciences, vol. 13, no. 1, pp. 38-41, Elsevier, Jan 2011.
The definitive version is available at http://dx.doi.org/10.1016/j.solidstatesciences.2010.10.003
Keywords and Phrases
Dimer Formation; Diselenide; Divalent Metals; Doped Sample; High Pressure; Highest Temperature; Linear Behavior; Magnetic Ordering; Magnetic Susceptibility Measurements; Metallic Resistivity; Numerical Values; Structure Type; Chalcogenides; Diffraction; Lead; Magnetic Susceptibility; Rare Earth Compounds; Selenium; Selenium Compounds; X Ray Diffraction; X Ray Powder Diffraction; X Rays; Crystal Structure
International Standard Serial Number (ISSN)
Article - Journal
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