RbCeX2 Crystal (X = S, Se, Te): Pressure-Induced Spin-Selective Gapless Transition and Response Properties

Crystal structures, electronic, and magnetic properties of RbCeX2 (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 alpha-spin gap of 0.46 eV while its beta-gap is 2.30 eV. A pressure of 10 GPa completely suppresses the alpha-spin gap of RbCeTe2 and reduces it beta-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 RbCeTe2 renders this compound a potential pressure induced MS -> SGS switching material. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, the crystal structures, electronic, and magnetic properties of RbCeX2 (X = S, Se, Te) crystals under a pressure of up to 10 GPa were investigated using DFT calculations. It was found that the ferromagnetic phase is slightly more stable than the antiferromagnetic phase for all compounds and pressures. Furthermore, a pressure-induced transition from a magnetic semiconductor to a spin gapless semiconductor was observed only in the case of the X = Te compound.