Structure, piezoelectric and multiferroic properties of Bi(Ni0.5Mn0.5)O3-modified BiFeO3–BaTiO3 ceramics

(0.725 − x)BiFeO3–0.275BaTiO3−xBi(Ni0.5Mn0.5)O3 + 1 mol% MnO2 lead-free multiferroic ceramics have been fabricated by a conventional ceramic technique and the structure, multiferroic and piezoelectric properties of the ceramics have been investigated. All the ceramics sintered at 950 °C for 2 h possess a pure perovskite structure. XRD patterns show that a coexistence of rhombohedral and pseudocubic phases are formed at x = 0.05−0.07. The average grain size decreases and the range of the grain size distribution greatly becomes narrow after the addition of Bi(Ni0.5Mn0.5)O3. The dielectric peak becomes gradually diffusive with increasing x. A small amount of Bi(Ni0.5Mn0.5)O3 doping (x ≤ 0.02) maintain the ferroelectric (Pr = 16.7−19.3 μC/cm2), piezoelectric properties (d33 = 124−145 pC/N) and ME coefficient performance (α33 = 444.45–553.65 mV cm−1 Oe−1).