Effects of zirconium doping on the structural, dielectric, ferroelectric, piezoelectric, and magnetic properties of lead-free 0.67BiFe_0.97Ga_0.03O₃–0.33BaTi_1−x Zr _x O₃ ceramics

Here we report the structural, dielectric, ferroelectric, piezoelectric, and magnetic properties of zirconium-doped 0.67BiFe_0.97Ga_0.03O₃–0.33BaZr _x Ti_1−x O₃ (BFG–BZT) lead-free ceramics. Structural investigations reveal that the doped Zr⁴⁺ ions (up to x = 0.15) can be fully incorporated into the host lattice. Dielectric measurements demonstrate that with increasing Zr⁴⁺ content, both the ferroelectric Curie temperature T _C and the dielectric constant decrease monotonously, and that the dielectric constant exhibits relaxor behaviors upon Zr⁴⁺ doping. At the same time, the remnant polarization P _r increases and then decreases, with the maximum P _r ∼ 26 µC/cm² for x = 0.025. One of the noteworthy results is that the remanent magnetic moment at room temperature increases up to 0.17 emu/g with increasing x from 0 to 0.15, which is attributed to enhanced lattice distortions due to Zr⁴⁺ doping. The coexistence of strong ferroelectricity and ferromagnetism at room temperature implies that the BFG–BZT could be potential candidate materials for multiferroic device applications.