High- and Low-Temperature Crystal and Magnetic Structures of ε-Fe2O3 and Their Correlation to Its Magnetic Properties

• DOI: 10.1021/cm060993l
• Publication Date: 2006-07-05T20:25:39Z
• Authors: M. Gich; C. Frontera; A. Roig; E. Taboada; E. Molins; H. R. Rechenberg; J. D. Ardisson; W. A. A. Macedo; C. Ritter; V. Hardy; J. Sort; V. Skumryev; J. Nogués
• Keywords: Ferrimagnetism; Rietveld Refinement; Orthorhombic crystal system; Magnetic structure; Magnetism

The crystal and magnetic structures of orthorhombic ε-Fe2O3 have been studied by simultaneous Rietveld refinement X-ray neutron powder-diffraction data in combination with Mössbauer spectroscopy, as well magnetization heat-capacity measurements. It has found that above 150 K, the polymorph is a collinear ferrimagnet moments directed along axis, whereas ordering below 80 K characterized square-wave incommensurate structure. transformation between these two states second-order phase transition involves subtle structural changes mostly affecting coordination tetrahedral one octahedral Fe sites. temperature dependence properties discussed light results.