Structural, dielectric, and multiferroic properties of Ta 2 O 5 -modified BiFeO 3 –BaTiO 3 –LaFeO 3 solid solutions

In this work, a series of Ta 2 O 5 -doped 0.675BiFeO 3 –0.3BaTiO 3 –0.025LaFeO 3 − x mol% Ta 2 O 5 ( x = 0, 0.25, 0.50, 0.75, 1.0, 1.25) multiferroic ceramics were synthesized by solid-state reaction. The effects of Ta 5+ doping on their phase structure, morphology, dielectric, ferroelectric, magnetic, and magnetoelectric properties were assessed. All samples were found to crystallize in perovskite structures, and the grain size was remarkably decreased by Ta 5+ doping. Ta 2 O 5 was beneficial to the dielectric properties, with the dielectric constant rising from 829 for undoped ceramic to 1149 for x = 1.25 at 100 Hz. The remnant polarization P r and coercive field E c decreased as x increased, indicating the worsening of ferroelectric behavior. In comparison, the ferromagnetism was evidently enhanced with increasing content of Ta 2 O 5 , and the remanent magnetization M r peaked at 0.035 emu/g for x = 0.75. The magnetoelectric coefficient α ME reached the maximum (418.68 mV/cm·Oe) for x = 0.25 at 200 Oe and 10 5 Hz.