NEW SPIN-REORIENTATION TRANSITION IN IRRADIATED SINGLE-CRYSTAL HEMATITE

It is experimentally observed that irradiation of single crystal hematite Fe2O3 leads to a decrease of the Morin spin-reorientation transition temperature and to the appearance of a reverse transition, i.e. to recovery of a weakly ferromagnetic phase at very low temperatures. Parameters of the new transition depend on the type and energy of particles. The possible reasons for the new transition and the formation mechanism of the disordered zones produced by atom-atom collision cascades are discussed. The splitting of the Mossbauer spectra in the temperature interval of the new transition undoubtedly shows that it is a first-order transition.