Magnetic Domain Walls in Single-Phase and Phase-Separated Double Exchange Systems

TL;DR

This paper analyzes the structure and energies of different magnetic domain walls in double exchange ferromagnets, revealing how phase separation influences domain wall types and potentially affects transport properties in manganate films.

Contribution

It introduces a comparative study of smooth, abrupt, and stripe domain walls in double exchange systems, highlighting the role of phase separation in domain wall energetics and structure.

Findings

Abrupt Ising-type walls have lower energy at low carrier concentrations.

Stripe walls involve phase separation and may influence transport properties.

Different domain wall types are energetically favored depending on carrier concentration.

Abstract

We investigate the structure of magnetic domain walls in a classical double exchange ferromagnet, evaluating domain wall energies and charges. Three different cases are studied: (i) a conventional smooth Bloch wall, (ii) an abrupt Ising-type wall, which is shown to have lower energy at small values of carrier concentration, and (iii) stripe wall, corresponding to the two ferromagnetic domains being separated by a stripe of another, antiferromagnetic, phase. General aspects of energy balance and geometry of phase-separated states are discussed in this context. It is speculated that domain walls of the latter type may be responsible for the unusual transport properties of certain manganate films.