Ferroelectric Properties of TGS Crystals with Cr Concentration Gradient

Abstract

In this paper certain peculiarities of the ferroelectric behavior of the TGS crystals with tailored non-uniform distribution of the impurity Cr^{3 +} are considered. The dielectric hysteresis loops of the TGS:Cr samples were characterized by the large shifts both along the polarization P axis and along the electric field axis. It is established that the unipolarity coefficient and pyroelectric signal of the samples with the impurity gradient have remained stable at the repeated cycles of heating—cooling. The obtained results are explicated within the framework of the phenomenological approach taking into consideration the gradient term in the Landau-Ginzburg free energy.

Keywords:

• Compositionally graded ferroelectrics
• ferroelectric hydrogenous crystals
• internal fields
• unipolarity