Compositional dependence of ferromagnetic and magnetoelectric effect properties in BaTiO3–BiFeO3–LaFeO3 solid solutions

Abstract

Multiferroic ceramics consisting of barium titanate (BaTiO₃, BT), bismuth ferrite (BiFeO₃, BFO), and lanthanum ferrite (LaFeO₃, LFO), namely (1 − x)(0.96BaTiO₃–0.04BiFeO₃)–xLaFeO₃ (BT–BFO–xLFO, where x = 0.1–0.5), were synthesized by the sol–gel method. The crystal structure, microstructure, and dielectric, ferromagnetic, and magnetoelectric properties of the ceramics were systematically investigated. Structural analysis of BT–BFO–xLFO solid solution showed a pure perovskite structure. The Rietveld refined XRD data fitted well with an orthorhombic structure (Pbnm space group). BT–BFO–0.4LFO and BT–BFO–0.5LFO exhibited initial dielectric constants of 2114 and 1741, respectively, at 20 Hz, followed by fast decay with increasing frequency. In comparison, the BT–BFO–xLFO ceramics with x = 0.1–0.3 showed excellent stability. Remarkably improved ferromagnetic properties were obtained for BT–BFO–0.4LFO, and the remnant magnetization increased from 0.008 to 0.666 emu g⁻¹ when x was increased from 0.1 to 0.4. The maximum value of the magnetoelectric coefficient reached 354 mV (cm⁻¹·Oe⁻¹) for the ceramic with x = 0.4 at 1000 kHz and 1 kOe.