Preparation And Electrical Properties Of(Ba_0.85Ca_0.15)(Zr_0.1Ti_0.9)O₃ Based Lead-free Piezoelectric Ceramic

Piezoelectric ceramics are used in the broad range of individual applications, such as surface acoustic wave devices, ultra sound transducers, sensors and other electronic devices, owing to their excellent electromechanical properties. Lead Zirconate Titanate(PZT) piezoceramics are one of the most widely used piezoelectric materials since 1954. However, one of the major shortcomings of these materials is their high lead content(~60wt% of lead oxide), presenting a possible ecological pollution while in the use and disuse. With the increasing awareness of environmental protection, seeking the lead-free and high performance piezoceramics is an important direction of current piezoceramics research.(Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 ceramics have been reported one of the most studied lead-free piezoceramics, which can be comparable with the lead-based piezoceramic materials. In order to enhance the electrical properties of the BCZT-based materials systems and overcome the shortcomings of high sintering temperatures and the low Curie temperature, we improved the preparation process, doping and composite modified. In this paper, systematic studies on the preparation of ceramics powder by molten salt method, doping modification and different lead-free piezoceramics system composite are performed as follows:1.(Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 lead-free piezoceramics were prepared by solid state method and molten salt method respectively, the process parameters such as molten salt ratio, calcining temperature and sintering temperature were studied. The experimental results show that the BCZT powders were synthesized by molten salt method can effectively reduce the calcining temperature 450℃ and the sintering temperature 150℃ and improve the activity of the powder.2.(Ba0.85Ca0.15)(Zr0.1Ti0.9)O3-x mol% Gd2O3 were prepared by conventional solid state method. A comprehensive analysis of phase structure, microstructure, dielectric, diffuse phase transition, ferroelectric and piezoelectric properties are presented. The results showed that amphoteric rare earth ions Gd3+ can improve its electrical properties about 80 p C/N when x=0.2.3.(Ba0.85Ca0.15)(Zr0.1Ti0.9)O3- x wt% 0.852(Bi0.5Na0.5)Ti O3- 0.12(Bi0.5K0.5)Ti O3- 0.028 Ba Ti O3 systems were designed and prepared by traditional solid state method. Effect of BKNT-BT on phase structure, microstructure, diffuse phase transition and electrical properties were systematically investigated. Studies have shown that BKNT-BT can improve the performance of piezoelectric property of the BCZT piezoceramics about 110 p C/N when x=1.