Magnetization and Neutron Diffraction Studies on Nanocrystalline Tetragonal SrFeO3−δ

Magnetization, AC susceptibility and neutron diffraction measurements are carried out on a nanocrystalline tetragonal SrFeO3−δ system prepared through solid-state reaction. Observed coercivity is due to uncompensated spins from the surface of the nanoparticle and broken bonds at the surface. Finite size effect plays a major role in hysteresis. The irreversibility in magnetization above the Néel temperature (TN) is due to the short-range correlation effect and the presence of local anisotropy field. Based on magnetization, AC susceptibility and neutron diffraction studies, we conclude that the nanocrystalline tetragonal SrFeO3−δ is an antiferromagnet with Néel temperature around 79 K.