Effect of N5+ ion irradiation on l-ornithine monohydrochloride single crystals: an organic nonlinear optical material

Abstract

In this work, the authors have grown good-quality single crystals of l-ornithine monohydrochloride (LOHCL), an organic nonlinear optical material, in the aqueous solution by the slow cooling technique. N5+ ion irradiation of three different doses (i.e. 1 × 1016, 5 × 1016 and 1 × 1017 ions/cm2) at room temperature was done on the cut and polished crystal specimen of appropriate size from the grown crystal. A detailed study of FT-Raman spectroscopic was carried out to see the effect of irradiation on structure and vibrational modes of the LOHCL crystal. The results revealed that there is no structural modification even at high doses except the variation in peak intensity, which indicates that the grown crystals of LOHCL have good stability and also confirms that the nitrogen ions do not substitute into the crystal lattice. The UV–Vis–near-infrared spectroscopic study was done on all the samples to see the effect of irradiation and various optical parameters such as transmittance (∼50–70%), absorption coefficient, energy band gap (∼4.75–4.96 eV), extinction coefficient, refractive index (∼1.31–1.24), optical permittivity (∼1.7–1.6) and susceptibility (∼0.7–0.6). The calculated optical parameters were found to vary with change in doses.