Semiconducting (Half-Metallic) Ferromagnetism in Mn(Fe) Substituted Pt and Pd Nitrides

TL;DR

This study uses first principles calculations to explore the electronic and magnetic properties of Mn- and Fe-doped PtN2 and PdN2, revealing potential new ferromagnetic semiconductors and half-metals with preserved crystal symmetry.

Contribution

It introduces a new class of diluted ferromagnetic semiconductors and half-metals based on transition metal substitution in nitrides, expanding the understanding of their electronic properties.

Findings

Fe-substitution induces half-metallicity in PtN2 and PdN2.

Mn-substitution results in semiconducting ferromagnets.

The crystal symmetry remains cubic after substitution.

Abstract

Using first principles calculations as based on density functional theory, we propose a class of so far unexplored diluted ferromagnetic semiconductors and half-metals. Here, we study the electronic properties of recently synthesized $ 4d $ and $ 5d $ transition metal dinitrides. In particular, we address Mn- and Fe-substitution in PtN$_2$ and PdN$_2$. Structural relaxation shows that the resulting ordered compounds, Pt$_{0.75}$(Mn,Fe)$_{0.25}$N$_2$ and Pd$_{0.75}$(Mn,Fe)$_{0.25}$N$_2$, maintain the cubic crystal symmetry of the parent compounds. On substitution, all compounds exhibit long-range ferromagnetic order. While both Pt$_{0.75}$Mn$_{0.25}$N$_2$ and Pd$_{0.75}$Mn$_{0.25}$N$_2$ are semiconducting, Fe-substitution causes half-metallic behavior for both parent materials.