Enhanced electrical properties of BNKT-BMN lead-free ceramics by CaSnO doping and their bioactive properties

There is an increasing interest in using piezoelectric materials, including lead-free piezoceramics for medical applications. As a result, more attention has been placed on investigating the biological properties of these materials. In this research experiment, electrical, mechanical, and biological properties of lead-free 0.99Bi 0.5 (Na 0.8 K 0.2 ) 0.5 TiO 3 -0.01Bi(Mg 2/3 Nb 1/3 )O 3 or 0.99BNKT-0.01BMN doped with CaSnO 3 (CSO) were investigated. The samples were synthesized by a modified solid-state reaction technique. X-ray diffraction (XRD) analysis showed that the samples presented a single perovskite phase. After adding CSO, electrical properties such as energy storage density (maximum W rec = 781 mJ cm −3 ) and electro-strain properties (maximum S max = 0.3%) were improved at room temperature. Mechanical properties were also enhanced for the modified samples with maximum values for Vickers hardness ( H V ) and elastic modulus ( E m ) of 6.11 GPa and 135 GPa, respectively. Biological assays for cytotoxicity, indicated that the samples had high cell viability, while the simulated body fluid (SBF) test revealed a moderate apatite forming ability. The samples were then coated with hydroxyapatite to improve their apatite-forming ability. The SBF testing for the coated samples showed that the coated samples had high apatite-forming ability. The obtained results pointed to the possibility of ceramics being used for multifunction electrical devices at room temperature and biomaterial applications. The CSO additive enhanced the electrical and mechanical properties of 0.99BNKT-0.01BMN ceramics. Biological tests on x = 0.02CSO samples showed moderate apatite formation in the SBF test and good cell viability in the cytotoxicity test.