Investigation of the Optical and Dielectric Properties of the Urea L-malic Acid NLO Single Crystal

Single crystals of urea L-malic acid were grown by the slow evaporation technique. The single crystal X-ray diffraction analysis reveals that the crystal belongs to the monoclinic system. The optical transmission study reveals the transparency of the crystal in the entire visible region and the cut off wavelength has been found to be 210 nm. The optical band gap is found to be 5.90 eV. Optical constants such as the band gap, refractive index, reflectance, extinction coefficient and the real (εr) and imaginary (εi) components of the dielectric constant and electric susceptibility were determined from the UV-VIS-NIR spectrum. Dielectric constant and dielectric loss of urea L-malic acid are measured in the frequency range from 50 Hz to 5 MHz at different temperatures. The relative second harmonic generation efficiency of urea L-malic acid crystal has been tested by Kurtz-Perry powder technique.