POLARIZED-NEUTRON STUDY OF HEMATITE

Polarized-neutron studies on natural and synthetic single crystals of hematite have shown that the 180\ifmmode^\circ\else\textdegree\fi{} antiferromagnetic domain walls are removed in low fields as the parasitic ferromagnetism of the high-temperature phase is saturated, and the remaining 120\ifmmode^\circ\else\textdegree\fi{} walls are removed by the application of higher fields. No memory effect was observed for the antiferromagnetic domain configuration as the crystal was cycled through the spin-axis transition temperature. The spin density of the ferromagnetic component of the spin system was found to be different from that of the antiferromagnetic component.