Molecule Derived Synthesis of Nanocrystalline YFeO₃ and Investigations on Its Weak Ferromagnetic Behavior

A new Y−Fe alkoxide, [YFe(OPr i ) 6 (Pr i OH)] 2, is used in the sol−gel process to obtain the orthoferrite, YFeO 3 . The Y/Fe stoichiometry (1:1) and Y−O(R)−Fe chemical links in the single molecular precursor kinetically control the formation of metastable YFeO 3 which is otherwise difficult to prepare due to the easy formation of the garnet composition, Y 3 Fe 5 O 12 . TG/DTA analysis showed the crystallization of YFeO 3 at 680 °C, which was confirmed by XRD data. The powders obtained were nanocrystalline (TEM) and the only crystalline compound present between 600 and 1300 °C was monophasic YFeO 3 . The absence of garnet and other iron-containing residual phases observed in previous studies was confirmed by temperature-dependent Mössbauer and magnetization measurements. The magnetization data support a weak ferromagnetic behavior and reveal low- and high-field regimes in M−T and M−H curves, corresponding to magnetocrystalline and antisymmetric-exchange anisotropy, respectively.