The Mossbauer spectra of single crystals of alpha -Fe₂O₃ have been measured (i) close to the Morin transition at T_M approximately=260K, (ii) at 4.2K in magnetic fields parallel to the (111) axis in the region of the spin-flop transition, and (iii) at temperatures below T_M in magnetic fields perpendicular to the (111) axis. The first two transitions show a coexistence of two magnetic phases over a range of temperatures and fields respectively, confirming their first-order character, although no hysteresis was observed. The width of the transitions showed a strong dependence on small levels of impurity and on strains. In the third transition a gradual reorientation of all the spins towards a direction in the (111) plane perpendicular to the applied field was observed. This transition was incomplete at the highest fields and temperatures used (10.0 T at 245K).