Magnetic properties of GaFeO3 prepared by slow cooling and quenched heat treatment method

The ferrimagnetic and piezoelectric materials GaFeO3 were prepared by slow cooling and quenching method, and studied by X-ray diffraction, neutron diffraction and Mossbauer spectroscopy. The crystal structures of samples were found to be orthorhombic with the lattice constants of the slowly cooled sample a = 8.7457, b = 9.3921, and c = 5.0816 angstrom, and those of the quenched sample a = 8.7462, b = 9.3896, and c = 5.0809 angstrom. The different behaviours of magnetic structure between two samples appeared by Mossbauer measurement. For the quenched sample, Neel temperature was 210 K, while it increased to 260 K for the slowly cooled sample. The decrease of magnetic transition temperature originates from distributions of magnetic Fe ion at four cation sites and the strength of exchange interaction between magnetic ions. (C) 2006 Elsevier B. V. All rights reserved.