Electrostriction effect in glass

The longitudinal electrostriction tensor component Q₁₁ in polarization notation and M₁₁ in electric field notation for sodium trisilicate glass and sodium aluminosilicate glass has been measured by the converse method, i.e. by measuring the slope of the uniaxial stress dependence of the dielectric constant at various frequencies. For sodium trisilicate glass, the Q₁₁ coefficient strongly depends on the frequency at which the capacitance was measured and shows a maximum near the frequency of 150 Hz, which is the ionic relaxation frequency of the glass. For sodium aluminosilicate glass, the relative change in the dielectric constant in response to a uniaxial stress was, however, found to be much smaller. We construct a sodium ion hopping model to explain qualitatively the results.