Tailoring composition in the (1-x)(Bi0.5Na0.5)TiO3- x BaTiO3 lead-free system for ultrasonic transduction: characterization of submicron structured ceramics from nanopowders

In this work dense and fine grained, submicron structured (?500nm), ceramics of (Bi0.5Na0.5)0.96Ba0.04TiO3 (BNBT4) were prepared from nanopowders and studied as candidates for ultrasonic transducer materials. Material parameters were obtained by analysis of the resonance spectra using Alemany et al. software. The real part of the set of room temperature coefficients from thin disks of the best performing materials (??33 = (416 -16 i), d31= (-22.68 + 0.55 i)pC/N-1, kt= 44.5%, kp=21.1%) can be compared with those reported and d33 (95 pC.N-1) is higher, despite of the lower grain size. Coefficients were as well determined from resonance of thickness-poled and length excited plates (??11= (402 -89i), d15=(108.3 - 21.4 i) pC.N-1 and k15=39.2%). This set of properties is advantageous for applications as ultrasonic transducer material compared with the properties of BNT or BNBT6 compositions