The influence of applied mechanical stress on the birefringence of (N(CH_{3})_{4})_{2}ZnCl_{4} crystal in the temperature region of its incommensurate phase was investigated using Senarmonth's method (λ = 633 nm). The value of pinning force for the samples with different defectiveness was experimentally determined.
A new optical method for measuring the optical activity of crystals is developed. Temperature dependence of gyration component g_{11} of ferroelectric lead germanate is measured. The obtained results confirm that lead germanate may be considered as a gyroelectric crystal.
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.