Hydrothermal synthesis, characterization and composition-dependent magnetic properties of LaFe1−x Cr x O3 system (0≤x≤1)

Abstract: Hydrothermal synthesis, characterization and magnetic properties of a series of ABO3-perovskites LaFe1−x Cr x O3 (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. [Copyright &y& Elsevier]