Profs Vidal Barrón and José Torrent of the University of Córdoba, in cooperation with other researchers from Stanford University (USA), Instituto de Ciencia de Materiales de Madrid, Umeå University (Sweden), Chinese Academy of Sciences,  and Sandia National Laboratories (USA) have studied the magnetic and structural properties of a ferrimagnetic form of ferrihydrite that is produced as an intermediate phase in the transformation of 2-line ferrihydrite into hematite.
Their results represent an important conceptual advance in understanding the nature of structural disorder in ferrihydrite and its relation to the magnetic structure. In addition, the pathway the authors identified for forming ferrimagnetic ferrihydrite potentially explains the magnetic enhancement that typically occurs during formation of aerobic soils. Their results also suggest that ferrimagnetic ferrihydrite could form naturally at ambient temperature given sufficient time. This would have substantial implications for the paleoclimatic interpretation of the magnetic properties of soils of many regions.

Reference: Michel, F.M., Barrón, V., Torrent, J., et al. (2010) Ordered ferrimagnetic form of ferrihydrite reveals links among structure, composition, and magnetism. PNAS 107:2787-2792.