Microcrystalline Gd2MoO6 prepared by combined mechanochemical/thermal process and its magnetic properties

Gadolinium oxymolybdate, Gd2MoO6 (monoclinic, C2/c) was prepared via nonconventional mechanochemical/thermal process from powdered oxide precursors (Gd2O3 and (NH4)(2)MoO4). The effect of mechanical activation via high-energy ball milling on the reactivity of the stoichiometric Gd2O3+(NH4)(2)MoO4 mixture was studied by thermal analysis (TG-DSC) and Fourier-transform infrared spectroscopy. While thermal treatment of nonactivated mixture leads only to decomposition of (NH4)(2)MoO4 and formation of Gd2O3-MoO3 system, mechanical activation provides enough energy for a chemical reaction between both reactants. The product with an average crystallite size of approximately 1m shows a well-faceted morphology. The investigation of magnetic properties revealed antiferromagnetic coupling, which is attributed to exchange interactions.