Inverse Piezoelectric Properties of Rochelle Salt

The relation between the change of lattice spacing of the (021) planes of Rochelle salt as a function of the change in voltage applied along the a-axis of the crystal has been determined by x-ray methods over the temperature range from approximately 10^∘{}C to 30^∘{}C. Measurements with a microscope of the strain set up in the crystal, due to a change in voltage applied along the a-axis, indicate that there is a one to one correspondence between the change of lattice constant as measured by x-rays and as determined from the measurements of strain. The piezoelectric modulus, d₁₄, as determined by the inverse piezoelectric effect is larger than the values determined from the piezoelectric effect.