LOW-TEMPERATURE MAGNETIC-STRUCTURE OF ERBIUM IRON-GARNET

The magnetic and crystallographic structure of erbium iron garnet {Er3} [Fe2] (Fe3)O12 has been refined simultaneously from powder and single crystal neutron diffraction data. At 5 K the ferrimagnetic structure has a spin direction parallel to [100]. Magnetic moments of iron and erbium and canting angles for the erbium sublattices were derived in space group I4(1)/a c d for 5 K < T < 65 K. The magnetic moments of the two erbium sites are 6.9 mu-B and 4.3 mu-B at 5 K. An indication of further symmetry reduction of the magnetic structure from tetragonal to orthorhombic below 5 K is discussed.