Mechanosynthesis and magnetic properties of nanocrystalline LaFeO3 using different iron oxides

CRISTÓBAL, A.A.; BERCOFF, P.; BOTTA, P.M.; PORTO LÓPEZ, J.M.

MATERIALS RESEARCH BULLETIN

Elsevier

Lugar: Amsterdam; Año: 2008 vol. 44 p. 1036 - 1040

0025-5408

The synthesis of the orthoferrite LaFeO3 using high-energy ball-milling of La2O3 and Fe3O4 or a-Fe2O3oxides and subsequent thermal treatments of resulting powders was studied. The phase evolutionduring the mechanical treatment was analyzed by X-ray diffraction (XRD), differential thermal analysis(DTA) and scanning electron microscopy (SEM). Also,magnetic properties of the obtained materials weremeasured at room temperature by vibrating sample magnetometry (VSM). From 30 min ofmechanochemical activation the gradual disappearance of reactants and the formation of LaFeO3 wereobserved. For both reactive mixtures the reaction was completed after 3 h of milling. Magnetic hysteresisloops of thesemechanoactivated samples showed a significant ferromagnetic component in LaFeO3. Thisbehavior was interpreted on the basis of a spin-canting effect induced by the mechanochemicaltreatment. Thermal treatments allowed the relaxation of the distorted structure, resulting in theformation of the conventional antiferromagnetic LaFeO3 phase.