| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1594126 | Solid State Communications | 2010 | 5 Pages |
The phase transitions, electronic structures and optical properties of Mg2Si under high pressure were researched by using the first-principles density functional theory. The calculated results demonstrate that Mg2Si undergoes two pressure-induced phase transitions: one is the transition from the cubic anti-fluorite (Fm3̄m) structure to the orthorhombic anti-cotunnite (Pnma) structure at 8.38 GPa, and the other is the transition from the orthorhombic anti-cotunnite structure to the hexagonal Ni2In-type (P63m̄mc) structure at 28.84 GPa. A good agreement between the calculated transition pressures and the previous experimentally measured results has been found. The structural parameters of the high-pressure phases are characterized in detail; the discrepancy between the calculated and experimental results for the anti-cotunnite phase is pointed out and analyzed. Finally, the electronic and optical properties of both the ambient anti-fluorite and the high-pressure phases are discussed; they show that Mg2Si has become metallic at high pressure.
