Phase separation and enhanced charge-spin coupling near magnetic transitions

TL;DR

This paper investigates how electronic compressibility changes near magnetic transitions, revealing potential for charge instabilities and phase separation in magnetic materials.

Contribution

It introduces a framework linking magnetic order to charge instabilities via compressibility changes, highlighting the possibility of phase separation in various magnetic systems.

Findings

Compressibility decreases significantly near magnetic transitions.

Charge instabilities can emerge due to reduced compressibility.

Phase separation tendencies are identified in specific magnetic materials.

Abstract

The generic changes of the electronic compressibility in systems which show magnetic instabilities is studied. It is shown that, when going into the ordered phase, the compressibility is reduced by an amount comparable to the its original value, making charge instabilities also possible. We discuss, within this framework, the tendency towards phase separation of the double exchange systems, the pyrochlores, and other magnetic materials.