Abstract
The reaction of a stoichiometric ratio of Pb, S and PbI 2 at 4 GPa and 600 °C yields Pb 4 S 3 I 2 , a compound that has not been reported in the ambient pressure PbS-PbI 2 system. Its crystal structure, determined from single crystal X-ray diffraction data, is orthorhombic (space group Pnma) with a = 8.1293(6) Å, b = 15.5613(11) Å, c = 8.1820(6) Å, and Z = 4 at ambient temperature and pressure. The structure consists of sheets of distorted edge-sharing lead-centered polyhedra and saw-tooth-shaped lead-lead bonded chains. Density Functional Theory based band structure calculations suggest Pb 4 S 3 I 2 to be an indirect band gap semiconductor, and, consistently, a band gap value of approximately 1.6 eV is determined by diffuse reflectance measurements. The material is diamagnetic above 1.8 K.
Original language | English (US) |
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Pages (from-to) | 49-53 |
Number of pages | 5 |
Journal | Solid State Sciences |
Volume | 91 |
DOIs | |
State | Published - May 2019 |
All Science Journal Classification (ASJC) codes
- General Chemistry
- General Materials Science
- Condensed Matter Physics
Keywords
- High pressure
- Lead chalcogenide halide
- Single crystal X-ray diffraction
- Solid state reaction