Hydrothermal synthesis, characterization and composition-dependent magnetic properties of LaFe1−xCrxO3 system (0≤x≤1)

Hydrothermal synthesis, characterization and magnetic properties of a series of ABO₃-perovskites LaFe_1−xCr_xO₃ (0≤x≤1) are reported. The alkalinity in initial reaction mixtures plays a critical role in controlling the designed stoichiometry of the final compositions. Their magnetic properties are strongly dependent on the compositions and a maximum magnetic moment is found for the sample at x=0.5. Weak ferromagnetic interaction observed for the samples from x=0 to 0.9 arises from the presence of Fe-O-Fe antisymmetric exchange and Fe-O-Cr superexchange interaction. The weak ferromagnetism as well as the linear variation of the lattice parameters implies the possible random distribution of Fe and Cr ions in B sites of the perovskites. The evolution of magnetic ordering transition temperatures has a close relationship with substituent ratios, for the competition of antiferromagnetism and ferromagnetism. The saturated magnetic moment shows a great improvement compared with that for the samples synthesized by solid state method.