Interferometric investigation of quadratic electrostriction in solid dielectrics

Electrostriction Is the strain response of a dlelectric material proportional to the square of an applled electric field. Thls effect Is related to 1he straindependence of 1he dlelectric function. The strain signal observed using optical inlerlerometry is a superposition of true electrostriction and other effects llke electrostalie lorces and thennal stresses. Therelore, ~Is necessary to have a fonnula that allows the measured values to be corrected lor these spurious eflects. In thls paper, a thermodynamic approach and 1he force law are used, comblnlng continuurn mechanics and Malewell's electromagnelic equalions, to derive a comiCiion formula. The res~ can be applled to measurements cl bo1h 1he longlludlnal and 1he transveraal effect in single crystals cl any symmetry.