The 18th International Conference on Internal Friction and Mechanical Spectroscopy (ICIFMS-18) was hold on September 12-15, 2017, in Foz do Iguaçu (Iguazu Falls), Brazil, organized by Universidade Estadual Paulista (UNESP) and Universidade Federal de São Carlos (UFSCar).
Plenary Talk: Lorena Pardo, “INTERNAL FRICTION CHARACTERIZATION IN LEAD-FREE FERROELECTRICS FOR ULTRASONIC GENERATION”
Ferroelectric solid solutions based on PbTiO3, mainly the one with lead zirconate (PbZrO3), also known as PZT, dominate the industrial applications of ferro-piezoelectric materials in polycrystalline form, also known as piezoelectric ceramics. The use of PbO in the fabrication of PZT and the end of the life-cycle of this omnipresent material involves hazards for the human health and the environment. European Union regulations arising in 2003 were the first to include the substitution of PZT with lead-free ferroelectrics. These regulations triggered the study of lead-free ferro-piezoelectrics and are now worldwide extended. This scientific research field experienced a strong growth from that time and has reached today a great level of maturity in some scientific themes, industrial transference and expansion of the topic from the scientific community to the society and to the business schools. In-operando characterization techniques of the materials as ultrasonic generators, including elastic, dielectric and piezoelectric losses are presented. Ecological, lead-free, ferroelectrics perovskites based on BaTiO3, and Ba substituted (Bi 0.5,Na0.5)TiO3, are here considered and matrix characterization of potentially applicable compositions is discussed.