Observation of the phase coexistence in  -Fe₂O₃at the Morin transition by synchrotron radiation white beam section topography

Abstract

Phase coexistence during the spin-reorientation Morin transition in haematite (α-Fe2O3) was investigated by observing phase boundary movements under the influence of temperature and of a magnetic field, using synchrotron radiation white beam section topography. The sample was a high quality (111) platelet shaped crystal, 1.1 mm thick. The phase boundaries are observed to move while remaining nearly parallel to (111). Nucleation of the weak ferromagnetic phase and pinning of interphase boundaries on defects located in the bulk of the crystal were observed. The observed behaviour patterns are discussed in terms of the elastic and magnetostatic energies involved.