Synthesis and anomalous magnetic properties of LaFeO3 nanoparticles by hot soap method

Highlights: → Nanocrystalline LaFeO3 particles were synthesized by using hot soap technique. → Average diameter of the obtained LaFeO3 nanoparticles was about 15 nm. → They exhibited superparamagnetic behavior with a blocking temperature of 30 K. → Large magnetization due to the presence of uncompensated surface spins was induced. - Abstract: Nanocrystalline LaFeO3 particles were synthesized at low temperatures by using hot soap technique. The synthesis was based on the thermal decomposition of organometallic compounds precipitated in a hot coordinating solvent. Moderate heat treatment at low temperature far below the combustion point of organic compounds produced spherical LaFeO3 nanoparticles with average diameter of about 15 nm. The crystalline phase, structure and particle size of obtained products were characterized by X-ray diffraction, infrared spectroscopy and transmission electron microscopy observations. In spite of the antiferromagnetic nature of bulk LaFeO3, the obtained nanoparticles exhibited anomalous large magnetization. Superparamagnetic behavior with a blocking temperature of about 30 K was observed in both magnetization and Moessbauer spectroscopic analyses.