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.