Studies on the thermal, optical and dielectric properties of a new nonlinear optical crystal — L-citrulline oxalate grown by slow evaporation technique

Abstract

In this paper we report the thermal, optical and dielectric properties of L-citrulline oxalate (LCO) monohydrate- a new nonlinear optical (NLO) organic crystal grown from aqueous solution by slow evaporation technique. It has good thermal stability up to 165°C. Optical transmittance of LCO is measured in the range 200–1000 nm and the crystal possesses a wide transparency region from 311nm to the far IR region. It has a band gap of 3.86eV. Hence the material is suitable for application as windows in spectral instruments in this region. The dielectric properties of the crystal have also been investigated. The dielectric constant obtained for LCO is higher at lower frequencies and then it decreases with increasing frequencies and saturates for further increase in the frequency. The second harmonic efficiency is found to be only 0.4 times that of KDP which can be improved by doping with alkali metals like lithium.