Intrinsic Magnetodielectric coupling in co- Substituted KBiFe2O5

Abstract

In this work, the co-substituted (Cobalt, Holmium) KBiFe2O5 (KBHFCO) brownmillerite is synthesized by the solid-state reaction route in polycrystalline form. The impact of rare earth Holmium and transition element Cobalt substitutions on the dielectric, magnetic, magnetodielectric, and magnetoimpedance properties of the prepared sample is investigated. The room temperature (RT) Rietveld refined X-ray diffraction (XRD) patterns confirm the monoclinic phase of the prepared sample having a P2/c space group. The RT magnetic study reveals that KBHFCO possesses weak ferromagnetic nature, and the unsaturation magnetization at a high magnetic field indicates the canted spin behavior. The frequency and magnetic field-dependent inverted butterfly-shaped magnetodielectric (MD) coupling show a maximum strength of ~ -0.6% and confirms the intrinsic nature behind the coupling. The butterfly-shaped frequency-dependent magnetoimpedance (MI ~ 0.6%) further confirms the capacitive origin of MD coupling, and the activation energy of the conductivity data addresses the negative MD coupling strength. The primary investigation on the origin of the MD coupling is anticipated from the presence of the inverse Dzyaloshinskii-Moriya interaction in the prepared KBHFCO sample.