Entry Date:
October 16, 2017

Examples of Electroceramic Materials and Applications

Principal Investigator Harry Tuller


PiezoPiezo imageelectricity is defined as a change in electric polarization with a change in applied stress (direct piezoelectric effect). The converse piezoelectric effect is the change of strain or stress in a material due to an applied electric field. The microscopic origin of the piezoelectric effect is the displacement of ionic charges within a crystal structure. In the absence of external strain, the charge distribution within the crystal is symmetric and the net electric dipole moment is zero. However when an external stress is applied, the charges are displaced and the charge distribution is no longer symetric and a net polarization is created. A material can be only piezoelectric if the crystallographic unit cell has no center of inversion.

In some cases a crystal posses a unique polar axis even in the unstrained condition. This can result in a change of the electric charge due to a uniform change of temperature. This is called the pyroelectric effect.