Phase separation in strongly correlated electron systems with spin-state transitions

Abstract

In some transition metal compounds, in particular in those with Co 3+ and Fe2+ having the d6 configuration, these ions can exist in different spin states, with the possibility of spin-state transitions between them. We demonstrate on a simple model that in doped compounds of such type there typically occurs a phase separation with the formation of inhomogeneous states, one of which corresponds to an undoped material with the low-spin state of Co3+ the other one with intermediate-spin state and delocalized eg electrons. The generic phase diagram of such systems is constructed. © 2010 IOP Publishing Ltd.