Heavy Fermion metal Fe16N2 and its giant magnetic moment

TL;DR

This paper proposes a new model for the strong ferromagnetism in Fe16N2, inspired by heavy fermion systems, emphasizing localized Fe-N clusters and electron interactions that lead to giant magnetic moments.

Contribution

It introduces a novel model linking localized orbitals and electron interactions to ferromagnetism in Fe16N2, supported by LDA+U simulations.

Findings

Fe-N clusters create non-uniform charge density

Enhanced U correlates with increased magnetic moment

Simulation results support the proposed model

Abstract

A new model is proposed for the strong ferromagnetism associated with partially localized orbitals in the Fe16N2 metallic system which draws substantially from models of heavy fermion metals. The basic idea is that the spatially isolated Fe-N clusters generate non-uniform charge density and increase the d-d electron interaction significantly, leading to a highly spin polarized configuration for low lying 3d orbitals. Simulation based on LDA+U method is performed to illustrate the correlation between enhanced U and giant magnetic moment.