Dielectric relaxation and pyroelectric behaviour of betaine potassium iodide dihydrate

Abstract

Betaine potassium iodide dihydrate (BKI) is a new compound of the aminoacid betaine with a triclinic symmetry and with the space group P1 at room temperature. It undergoes a phase transition at 100 K. In this paper we report a detailed study of the dielectric relaxation and of the pyroelectric properties of this compound in the temperature range 20-300K. A microscopic interpretation of dielectric properties is presented by doing a comparison between the dielectric dispersion behaviour and the results obtained in the study of Raman scattering of BKI.

Keywords:

• Betaine potassium iodide dihydrate
• dielectric relaxation
• pyroelectric coefficient
• polarisation reversal
• order-disorder phase transition