Induced and spontaneous strain in ferroelectric ferroelastic tanane

Abstract

Physical properties of the organic material tanane¹ do not allow sufficiently accurate polarization measurements. As an alternative, the following order parameters were studied: spontaneous shear strain x ₆, (linearly coupled to spontaneous polarization P ₃), and spontaneous birefringence Δn ₆, shown to be proportional to the spontaneous strain. Results of induced birefringence and strain, above and below the transition temperature (T_c = 13.5°C), are reported and discussed.