Thermodynamics of carrier-mediated magnetism in semiconductors

A.G. PETUKHOV; L. MAKINISTIAN; S.C. ERWIN; R. ABOLFATH; I. ZUTIC

New Orleans, USA

Congreso; APS March Meeting; 2008

We propose a model of carrier-mediated ferromagnetism in semiconductors that accounts forthe temperature dependence of the carriers2. The model permits analysis of the thermodynamic stability of competing magnetic states, opening the door to the construction of magnetic phase diagrams. As an example we analyze the stability of a possible reentrant ferromagneticsemiconductor, in which increasing temperature leads to an increased carrier density, such that the enhanced exchange coupling between magnetic impurities results in the onset of ferromagnetism as temperature is raised. We apply this approach to studying thermodynamic fluctuationsof magnetization in small systems such as bound magnetic polarons and magnetic nanoislands.