Speaker
Description
The magnetoelectric coupling effects and ferromagnetic properties of multiferroic bismuth ferrite (BiFeO₃, BFO) nanoparticles at the microscopic scale remain subjects of ongoing scientific discourse. In this study, two local hyperfine interaction techniques—time differential perturbed angular correlation (TDPAC) spectroscopy and transmission Mössbauer (TMS) spectroscopy—were employed to investigate local atomic-scale fields without altering the structural integrity of materials. The TDPAC data provide clear evidence of ferrimagnetic ordering at the non-magnetic sublattice Bi ions within BFO nanoparticles (BFO NPs). Additionally, the combined analysis of TDPAC and TMS reveals a pronounced magnetostrictive magnetoelectric coupling effect in BFO NPs, primarily governed by inhomogeneous compressive strain. To achieve a comprehensive characterization of the material, supplementary techniques—including high-resolution transmission electron microscopy, scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometry - were utilized. The findings suggest that lattice strain induced by particle boundaries in aggregates plays a pivotal role in modulating ferromagnetism and magnetoelectric coupling in BFO NPs.
