Structural Investigation and Zero-Field-Cooled Exchange Bias in Nanocrystalline LaFeO3

Abstract

In the present work, synthesis of nanocrystalline LaFeO3 by using a mechanochemical activation (ball milling) method with oxide precursors (La2 O 3 and Fe2 O 3) at low temperature is discussed. The thermal and X-ray diffraction studies were used to analyze the formation of intermediate phases during the growth of LaFeO3. The single crystallographic phase of LaFeO3 was confirmed using X-ray diffraction analysis. The detailed structural characteristics of the nanocrystalline LaFeO3 powders were studied by the Rietveld refinement using the FullProff program. Field emission scanning electron microscopy (FESEM) and AFM study revealed the formation of spherical morphology of the nanoparticles. TEM images confirm the formation of homogeneously distributed nanoparticles with their average particle size of about 36 nm. The magnetic measurements were carried on the as-prepared powder, both as a function of temperature and magnetic field. Results of field-cooled (FC) and zero-field-cooled (ZFC) magnetic measurements point out to the existence of spin glass (SG) phases. The exchange bias phenomenon at zero fields cooled is found in hysteresis loop measurements at low temperature.