Tuning phase structure and multiferroicity in Cu/Fe co-doped BaTiO3 ceramics

A/B-site co-doping is an effective strategy for inducing magnetism and magnetoelectric coupling in the conventional ferroelectrics. However, enhancing the coupling between A- and B-site ions remains a challenge. In this work, a series of Ba 1- x Cu ₓ Ti 0.9 Fe 0.1 O 3 ( x = 0, 0.025, 0.050, 0.075, 0.100 and 0.125) ceramics were synthesized and systematically investigated. A-site Cu doping not only reduces the hexagonal phase fraction, enhances room-temperature ferroelectricity, but also modulates the magnetic structure, leading to a transition from paramagnetic to spin-glass and later to antiferromagnetic- ferromagnetic-coexisted state. The sample with x = 0.075 exhibits simultaneous ferroelectricity and ferromagnetism at room temperature, along with remarkable magnetoelectric coupling. At low temperatures, the sample with x = 0.100 demonstrates the highest magnetodielectric coefficient, reaching 5.38%. This work proposes a novel approach to induce room-temperature multiferroicity and achieve enhanced magnetoelectric coupling.