Influence of Fe3+ and Co2+ co-doping on the electrical, magnetodielectric, and multiferroic properties of lead-free Ba0.7Sr0.3TiO3 ceramics

Abstract

This study explores the ambient temperature multiferroic behavior in lead-free Ba_0.7Sr_0.3TiO₃ ceramics co-doped with transition metal ions (Fe³⁺ and Co²⁺) synthesized via the solid-state reaction (SSR) method. The research systematically investigates the effects of transition metal co-doping on the structural, ferroelectric, dielectric, magnetic, and magnetodielectric properties of the ceramics. X-ray diffraction (XRD) analyses confirmed the formation of a monophasic crystalline structure with P4mm space group symmetry across all compositions. Raman spectroscopy further supported the presence of single-phase crystallinity, consistent with the XRD results. Scanning electron microscopy (SEM) revealed a decrease in grain size due to the incorporation of transition metal ions. Dielectric properties, measured across a frequency range of 1 kHz to 1 MHz, demonstrated frequency-dependent behavior. Ferroelectric P–E hysteresis curves exhibited a consistent reduction in polarization (P_s and P_r), while magnetic M−H loops showed an enhancement in magnetic properties. Magnetodielectric (MD) analysis validated the coupling between ferromagnetic and ferroelectric ordering. The sample exhibited significant magnetodielectric effects, demonstrating a notable MC% value of 5.83 %. These findings highlight the potential of this co-doped BST ceramic for use in advanced non-volatile multiferroic memory devices.