6. Conclusions

In this work, the strain mechanisms of two different lead-free ferroelectrics, the (1 − x)Ba(Zr_0.2Ti_0.8)O₃–x(Ba_0.7Ca_0.3)TiO₃ and the (1 − x)(Bi_1/2Na_1/2)TiO₃–xSrTiO₃, have been thoroughly investigated and analyzed in order to identify the different contributions to the electromechanical output. With the purpose of describing the relations between functional properties, crystal structure, and microstructure various different techniques were employed on different length scales. Special emphasis was done to elucidate different types of phase instabilities and their influence on the electromechanical properties. Moreover, the broad range of experiments performed also enabled an application-oriented characterization, as given in Appendix V for interested readers.