Magnetization and Mössbauer Studies of the Field Dependence of the Morin Transition in Hematite

The field dependence of the Morin transition in Hematite, $\alpha$-${\mathrm{Fe}}_2$ ${\mathrm{O}}_3$, was studied using the rotating sample magnetometer (RSM) and Mössbauer techniques. With fields in the basal plane, (111), as high as 20 kOe, the Morin temperature was found to decrease by about 10°C. In this range the transition of the antiferromagnetic (AF) axis from the trigonal direction [111] to the basal plane was found to be abrupt.