Investigations on the Domain Structure in Hematite by means of the Electron Beam Method

摘要: Shadow patterns have been obtained from crystals of hematite using the electron beam technique. These possess shadow-edge features which are shown to be consistent with that expected a domain structure. In many examined disappear on cooling at abouit -15 ?C and reappear heating. number cases containing relatively large amounts impurities, particularly titanium, either do niot change, or only appreciably lower temperatures. 1. INTROD-UCTION Electron beams previously employed (Germer 1942; Blackman & Griinbaum i957) study magnetic leakage field associated hexagonal cobalt. The present paper is concerned mainly study, similar methods, natural hematite. case particular interest as it has some properties characteristic weak ferromagnetic substance, though essentially antiferromagnetic in character. Neutron diffraction investigations show iron atoms arranged layers perpendicular threefold axis rhombohedral crystal; dipoles all lie same direction each layer but successive oppositely magnetized. pure xFe203 directions suffer change below about