Phase transitions of magnetic nanoclusters in metals and semiconductors

The interactions and phase transitions of magnetic nanoclusters embedded in nonmagnetic metals and semiconductors are investigated theoretically. As a consequence of the temperature dependence of the indirect interactions, it is shown that for semiconductors several ferromagnetic phase transitions are possible depending on the size of the nanoclusters, whereas for metals a single ferromagnetic phase transition occurs independently of the size of the nanoclusters. The spontaneous magnetization is evaluated in all cases.