Study of the glassy magnetic behaviour and charge-ordering phase transitions in La0.75Ca0.25FeO3-δ perovskite

In this work, La0.75Ca0.25FeO3-delta perovskite sample was prepared by the coprecipitation method. The nanoparticle was found to crystallize in the orthorhombic (Pbnm) phase as confirmed by X-ray diffraction (XRD) and transmission electron microscopic (TEM). The oxygen non-stoichiometry (delta) and magnetic states of iron ions (three magnetic sextets and non-magnetic doublet) were investigated by Mossbauer spectroscopy at room temperature (RT). The shape of the magnetic hysteresis loop of the sample reveals the existence of a weak ferromagnetism at RT. The magnetization vs. temperature curves, measured in the 9 to 200 K range, showed that the sample exhibits two magnetic-phase transition temperatures at 29 K (T-g) and 120 K (T-CO). The magnetization isotherms, M (H), around these magnetic-phase transition temperatures for the sample are analyzed.