The stabilizing role of itinerant ferromagnetism in inter-granular cohesion in iron

TL;DR

This paper introduces a simple energy functional based on itinerant ferromagnetism theory that accurately predicts interfacial energies in iron, highlighting the magnetic influence on grain boundary cohesion.

Contribution

It proposes a new energy functional incorporating local spin density extension to Stoner theory, explaining magnetic effects on grain boundary cohesion in iron.

Findings

Functional reproduces ab initio and experimental data

Magnetic structure influences inter-granular cohesion

Provides insight into atomic relaxation mechanisms at boundaries

Abstract

We present a simple, general energy functional for ferromagnetic materials based upon a local spin density extension to the Stoner theory of itinerant ferromagnetism. The functional reproduces well available ab initio results and experimental interfacial energies for grain boundaries in iron. The model shows that inter-granular cohesion along symmetric tilt boundaries in iron is dependent upon strong magnetic structure at the interface, illuminates the mechanisms underlying this structure, and provides a simple explanation for relaxation of the atomic structure at these boundaries.