Electronic phase separation in the pyrochlore double-exchange model

TL;DR

This paper investigates how geometrical frustration influences electronic phase separation in the pyrochlore double-exchange model, revealing phase separation between ferromagnetic and paramagnetic metals and relating findings to experimental observations in Mo pyrochlore oxides.

Contribution

It demonstrates that geometrical frustration induces a unique phase separation between ferromagnetic and paramagnetic metals in the pyrochlore double-exchange model, using Monte Carlo simulations and energy comparisons.

Findings

Phase separation occurs between ferromagnetic and paramagnetic metals.

Geometrical frustration plays a key role in the phase separation.

Relevance to spin-glassy metallic phases in Mo pyrochlore oxides.

Abstract

Electronic phase separation and related inhomogeneity is ubiquitously seen in strongly-correlated systems. A typical example is found between ferromagnetic metal and antiferromagnetic insulator in CMR manganese oxides. Here we demonstrate that the geometrical frustration brings distinctive aspects into the phase separation phenomena. From Monte Carlo simulation and a simple energy comparison for the pyrochlore double-exchange model, we show that such phase separation takes place between ferromagnetic and paramagnetic metals. We discuss the relevance of our results to a spin-glassy metallic phase found in Mo pyrochlore oxides under external pressure.