RbBiNb₂O₇: A new lead-free high-T_c ferroelectric

Ferroelectric materials, which have a reversible spontaneous polarization and generate an electric potential when subjected to a mechanical stress (piezoelectricity), have applications in nonvolatile random access memory devices and micro-electromechanical systems. Within this area, the development of high piezoelectric sensitivity in lead-free ferroelectric materials remains to date as a primary scientific challenge, driven by the toxicity of lead oxide and nowadays directives for environmental protection. Despite extensive research efforts, there are only a limited number of lead-free ferroelectric materials with a Curie temperature sufficiently high and the performance good enough for piezoelectric applications.