Phase separation and magnetoresistance in random-field magnetic polaron systems

The phase separation and magnetoresistive effect of small magnetic polaron systems is studied in a random-field Ising model. The ferromagnetic/paramagnetic (FM/PM) phase separation phenomenon appears when a random-field is applied on a spin lattice. Based on the phase separation picture, the conductance by an electron tunneling mechanism is simulated. The resistivity and magnetoresistance are calculated and analysed. The physics of metal-insulator transition due to the intrinsically spatial inhomogeneities in magnetic polaron systems is discussed.