Structural, electronic and magnetic properties of the Manganese telluride layers AMnTe2 (A=K, Rb, Cs) from first-principles calculations

TL;DR

This study uses first-principles calculations to analyze the structural, electronic, and magnetic properties of layered AMnTe2 compounds, revealing their ferromagnetic half-metallic nature and proposing a new Slater-Pauling rule.

Contribution

It provides the first detailed theoretical investigation of AMnTe2 compounds, identifying their ferromagnetic ground state and half-metallicity, and introduces a new version of the Slater-Pauling rule for these materials.

Findings

All compounds are ferromagnetic ground states.

Each compound exhibits half-metallicity with 4 μ_B magnetic moment.

Calculated properties include bulk modulus, pressure derivative, and energy gaps.

Abstract

Using first-principles electronic structure calculations based on density functional theory (DFT), we investigate the structural, electronic and magnetic properties of the layered ternary manganese tellurides: AMnTe2 (A = K, Rb, and Cs). Calculations are accomplished within the full-potential linearized augmented plane wave (FP-LAPW) using the generalized gradient approximation GGA formalism for the exchange correlation term. We have treated all ferromagnetic, antiferromagnetic and non-magnetic phases and found that the ferromagnetic is the ground-state for all studied compounds. Moreover, all three compounds under study are half-metals with a total spin magnetic per formula unit of 4 mu_B which is mainly localized at the Mn atoms. We express for these compounds a new version of the Slater-Pauling rule and discuss in detail the origin of the minority-spin gap. Finally, we have also calculated some other relevant quantities such as the bulk modulus B, the pressure derivative B', the virtual semiconducting gap Eg, and the half-metallic gap E_HM.