Study of neutron irradiation effect on Morin transition in hematite

Abstract

It is established by Mössbauer spectroscopy and slow neutron diffraction that temperature range of Morin transition in hematite changes depending on neutron irradiation dose, and above some critical values the transition is not observed at all. A fraction of iron ions with high-temperature orientation of moments which cause the sample weak-ferromagnetic characteristics decreases with temperature fall but does not disappear completely, and near 4 K it even rises. It is established that radiation defects causing the changes in Morin transition disappear at annealing of hematite on air at temperatures of 400–500 K.