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RESEARCH PRODUCT
Effect of pressure on the structural properties and electronic band structure of GaSe
Ulrich S. SchwarzMichael HanflandAndrés CantareroD. OlguínD. OlguínK. Syassensubject
DiffractionBond lengthCrystallographyPhase transitionExtended X-ray absorption fine structureBand gapChemistryAb initio quantum chemistry methodsElectronic structureCondensed Matter PhysicsElectronic band structureMolecular physicsElectronic Optical and Magnetic Materialsdescription
The structural properties of GaSe have been investigated up to 38 GPa by monochromatic X-ray diffraction. The onset of the phase transition from the e-GaSe to a disordered NaCi-type structural motif is observed near 21 GPa. Using the experimentally determined lattice parameters of the layered e-phase as input, constrained ab-initio total energy calculations were performed in order to optimize the internal structural parameters at different pressures. The results obtained for the nearest-neighbor Ga-Se distance agree with those derived from recent EXAFS measurements. In addition, information is obtained on the changes of Ga-Ga and Se-Se bond lengths which were not accessible to a direct experimental determination yet. Based on the optimized structural parameters, we report calculations of band gap changes of e-GaSe under pressure. The optical response and electronic band structure of the metallic high-pressure phase of GaSe are discussed briefly.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2007-01-01 | physica status solidi (b) |