Structure, piezoelectric and multiferroic properties of Bi(Ni_(0.5)Mn_(0.5))O_3-modified BiFeO_3-BaTiO_3 ceramics

摘要

(0.725 -x)BiFeO_3-0.275BaTiO_3-xBi(Ni_(0.5)Mn_(0.5)) O_3 + 1 mol% MnO_2 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 ℃ for 2 h possess a pure perovskite structure. XRD patterns show that a coexistence of rhom-bohedral 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(Ni_(0.5)Mn_(0.5))O_3. The dielectric peak becomes gradually diffusive with increasing x. A small amount of Bi(Ni_(0.5)Mn_(0.5))O_3 doping (x ≤0.02) maintain the ferroelectric (P_r = 16.7-19.3 μC/cm~2), piezoelectric properties (d_(33) = 124-145 pC/N) and ME coefficient performance (α_(33) = 444.45-553.65 mV cm~(-1) Oe~(-1)).