For 10 points, name this property discovered in Rochelle salts by Pierre and Jacques Curie, found in materials like quartz in which an electric response results from stress or strain on a material.
Along with dielectric constant, this property is diminished in the pyrochlore phase of a material. Tiersten developed a system of energy balances as an IEEE model for their activity. This behavior can be explained by coupling the equation setting displacement equal to permittivity times electric field with Hooke's law, then looking at the tensor elements. Materials with a center of symmetry cannot undergo this effect, which can be explained by noting that a change in the dipole configuration or density in a bulk material is accompanied by a change in the surface charge. For 10 points, name this property discovered in Rochelle salts by Pierre and Jacques Curie, found in materials like quartz in which an electric response results from stress or strain on a material.
Along with dielectric constant, this property is diminished in the pyrochlore phase of a material.
 piezoelectricity