Magnetic properties and Mössbauer study of perovskite LaMn0.5Fe0.5O3

Abstract

The wide application of LaMn0.5Fe0.5O3 perovskite is due to its very complex magnetic and structural properties. Orthorhombic perovskite structure samples were prepared by sol-gel method. The system has a special spin glass state (Néel temperature below freezing temperature). Therefore, there is a transition for the main magnetic phase from strong antiferromagnetism to ferrimagnetism and finally to superparamagnetism as the temperature increases. The typical ferromagnetic and antiferromagnetic competing exchange bias phenomenon appears in the M − H curve at 5 K. We have simulated the thermal and magnetic characteristics of the system through the XYZ model and particle swarm optimization and obtained accurate anisotropy parameters. The transitions of the Mössbauer spectra at different temperatures reflect the changes in the macroscopic magnetic properties of the system. Finally, we can explain the relaxation peak behavior of Mössbauer spectra well by the relationship between the relaxation hyperfine field and temperature. This study will provide a good illustration and reference for the magnetic nature of strongly magnetic disordered LaMn0.5Fe0.5O3 systems.