Ferroic materials are solids that possess at least one spontaneously ordered physical quantity that can be reversed by external fields. Depending on the type of order, one distinguishes ferroelectric, ferromagnetic, ferroelastic, and ferrotoroidal materials. When several of these ordering phenomena coexist, the material is termed multiferroic.

In ultrasound technology, ferroelectric and piezoelectric materials, such as lead zirconate titanate (PZT), lead magnesium niobate titanate (PMN-PT), and barium titanate (BaTiO₃), are employed as acoustic transducers. Direct and inverse piezoelectricity enable the conversion of electrical energy into mechanical motion and vice versa. An applied electrical voltage induces elastic deformation of the crystal lattice, thereby generating high-frequency mechanical waves (ultrasound). Thanks to their high coupling constants and stability, ferroelectric ceramics and single crystals are essential for medical ultrasound probes, non-destructive testing, and precision positioning systems in micro- and nanotechnology.

Contacts: Prof. Vladimir Shvartsman, Prof. Doru C. Lupascu