Abstract
Crystal structures, electronic, and magnetic properties of RbCeX_2 (X = S, Se, Te) crystals are investigated using periodic density functional theory (DFT) calculations under hydrostatic pressures up to 10 GPa. The ferromagnetic phase is slightly more stable than the anti-ferromagnetic one for all compounds and pressures. A pressure-induced transition from a magnetic semiconductor (MS) to a spin gapless semiconductor (SGS) is observed only in the case of the X = Te compound. In absence of imposed pressure, the X = Te exhibits a direct a-spin gap of 0.46 eV while its β-gap is 2.30 eV. A pressure of 10 GPa completely suppresses the a-spin gap of RbCeTe_2 and reduces it β-gap to 1.63 eV. This pressure-induced elimination of only one spin gaps is exclusive to the X = Te compound. This property distinguishes the Te compound from its two congeners. The pressure-response characteristics of RbCeTe_2 renders this compound a potential pressure-induced MS → SGS switching material.
NSTL
Elsevier