Density-functional-theory investigation of pressure induced semiconductor–metal transitions in the ferromagnetic semiconductor HgCr2Se4

Abstract

We investigate the electronic structures of the ferromagnetic semiconductor HgCr2Se4 by using a modified Becke and Johnson exchange potential. The energy gap calculated with the experimental lattice structure is in good agreement with the experimental value. When the pressure reaches 9.0 GPa, HgCr2Se4 becomes a so-called spin gapless semiconductor due to the closure of the spin non-conservation energy gap, and when the pressure increases to 11.4 GPa, the spin conservation energy gap closes, leading to a semiconductor–semimetal transition.