Model Hamiltonian parameters for half-metallic ferromagnets NiMnSb and CrO2

TL;DR

This paper uses the NMTO downfolding technique to derive effective Hamiltonian parameters for NiMnSb and CrO2, providing insights into their electronic structure and bonding mechanisms.

Contribution

It introduces minimal basis set model Hamiltonian parameters for half-metallic ferromagnets NiMnSb and CrO2 using NMTO downfolding.

Findings

Constructed NMTO Wannier orbitals for Mn-d and Cr-t2g.

Calculated effective hopping parameters for the materials.

Proposed minimal basis sets for modeling these ferromagnets.

Abstract

Using the recently developed Nth-order muffin-tin-orbital (NMTO) based downfolding technique we revisit the electronic properties of half-metallic ferromagnets, the semi-Heusler NiMnSb and rutile CrO2. The NMTO Wannier orbitals for the Mn-d and Cr-t2g manifolds are constructed and the mechanism of chemical bonding is discussed. The effective hopping Hamiltonian parameters are calculated using a NMTO downfolded basis set. We propose model Hamiltonian parameters with possibly minimal basis sets for both half-metallic ferromagnetic alloys.