The Growth and the Optical, Mechanical, Dielectric and Photoconductivity Properties of a New Nonlinear Optical Crystal—L-Phenylalanine-4-nitrophenol NLO Single Crystal

Abstract

Nonlinear optical single crystals of L-phenylalanine-4-nitrophenol have been grown by the slow evaporation method. The grown crystal was subjected to the single crystal X-ray diffraction analysis, to confirm that it belongs to the monoclinic crystal structure, with space group P21. The optical transmission study reveals the transparency of the crystal in the entire visible region and the cut off wave length has been found to be 320 nm. The optical band gap is found to be 3.87 eV. The transmittance of the L-phenylalanine-4-nitrophenol crystal has been used to calculate the refractive index (n), the extinction coefficient (K) and the real (εr) and imaginary (εi) components of the dielectric constant. The mechanical behaviour of the grown crystals was studied using Vicker’s microhardness tester. The dielectric constant and dielectric loss of L-phenylalanine-4-nitrophenol are measured in the frequency range of 50 Hz to 5 MHz at different temperatures. The photoconductivity study confirms the negative photoconductive nature of the sample.