Effect of Mn doping on structural and magnetic properties of GaFeO3

GaFe_1−xMn_xO₃ polycrystalline materials have been prepared by a solid state reaction (SR) and by the sol-gel (SG) method. The maximum Mn content amounts up to 10% and 40% for SR and SG preparation, respectively. All compounds in these composition ranges crystallize in space group P c 2₁ n derived from Rietveld refinement of X-ray powder patterns. The gradual incorporation of manganese is accompanied by a decrease in the cell volume. The ferrimagnetic transition temperature of T_c=282 K for GaFeO₃ decreases with Mn content and reaches T_c=149 K for x=0.4.