Carrier-Induced Breakdown of Ferromagnetism

Abstract

Magnetization, susceptibility and specific-heat data for PbSn(Mn)Te and Sn(Mn)Te will be reported for various carrier concentrations. For the first time a carrier-concentration–induced breakdown of a ferromagnetic state has been observed. Based on a simple geometrical argument, a phase diagram for this new transition in RKKY-driven systems will be derived and will be compared with the ferromagnetic–to–spin-glass transition predicted by the well-known Sherrington-Kirkpatrick model.