Insights into the Crystal Structure and Magnetodielectric Properties of High-Energy Ball Milled Sr Substituted LaFeO.

The effect of strontium substitution on the crystal tructure, as well as the magnetic, and electrical properties of lanthanum ferrite (LaFeO) synthesized by high-energy ball milling, is studied, with an emphasis on magnetodielectric coupling. X-ray diffraction (XRD) confirmed the successful synthesis of orthorhombic LaSrFeO for doping levels up to 0.2 mol. At 0.3 mol Sr, two phases appear: LaSrFeO and LaSrFeO, the latter being metastable. This phase vanishes at 0.5 mol. The Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS) analysis confirmed these results using a vibrating sample magnetometer (VSM), whose measurements show ferromagnetism at 0.1 and 0.3 mol Sr, attributed to crystal distortion, magnetic spin rearrangement, and as consequence, modifications in the double-exchange interactions. Dielectric tests reveal that higher Sr concentrations lead to increased relative permittivity, dielectric losses, and conductivity, linked to oxygen vacancy formation. This study demonstrates a room-temperature magnetodielectric coupling of 32% in Sr-doped lanthanum ferrite, highlighting its potential for technological applications.