TY - JOUR
T1 - A high-pressure phase with a non-centrosymmetric crystal structure in the PbSe–PbBr2 system
AU - Ni, Danrui
AU - Guo, Shu
AU - Powderly, Kelly M.
AU - Zhong, Ruidan
AU - Cava, Robert J.
N1 - Funding Information:
This work was supported by the ARO-sponsored MURI on Topological Insulators, grant W911NF-1210461 . K.M.P. acknowledges the support of the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1656466 .
Publisher Copyright:
© 2019 Elsevier Inc.
PY - 2019/12
Y1 - 2019/12
N2 - We report Pb3Se2Br2, a lead chalcogenide halide that has not been described in the ambient pressure PbSe–PbBr2 system, synthesized using a high-pressure solid-state method at 4 GPa and 700 °C. Its crystal structure is determined by single crystal X-ray diffraction to be body centered cubic and non-centrosymmetric (Th3P4 structure type, space group I4‾3d, #220) with a = 9.3200(4) Å at room temperature and ambient pressure, where it appears to be a metastable phase. The Pb atoms are coordinated by eight anions in a dodecahedron, with Se and Br occupying the same crystallographic site in a disordered 1:1 ratio to yield a normal valence compound. Pb3Se2Br2 is a semiconductor with an indirect band gap of 1.48 eV, determined by diffuse reflectance measurements. The indirect band gap is theoretically supported by density functional theory calculations.
AB - We report Pb3Se2Br2, a lead chalcogenide halide that has not been described in the ambient pressure PbSe–PbBr2 system, synthesized using a high-pressure solid-state method at 4 GPa and 700 °C. Its crystal structure is determined by single crystal X-ray diffraction to be body centered cubic and non-centrosymmetric (Th3P4 structure type, space group I4‾3d, #220) with a = 9.3200(4) Å at room temperature and ambient pressure, where it appears to be a metastable phase. The Pb atoms are coordinated by eight anions in a dodecahedron, with Se and Br occupying the same crystallographic site in a disordered 1:1 ratio to yield a normal valence compound. Pb3Se2Br2 is a semiconductor with an indirect band gap of 1.48 eV, determined by diffuse reflectance measurements. The indirect band gap is theoretically supported by density functional theory calculations.
KW - High pressure synthesis
KW - Lead chalcogenide halide
KW - Non-centrosymmetric structure
KW - Single crystal X-ray diffraction
KW - Solid state reaction
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U2 - 10.1016/j.jssc.2019.120982
DO - 10.1016/j.jssc.2019.120982
M3 - Article
AN - SCOPUS:85073230719
SN - 0022-4596
VL - 280
JO - Journal of Solid State Chemistry
JF - Journal of Solid State Chemistry
M1 - 120982
ER -