Synthesis, spectral, optical and electric studies of N,N′-diphenylguanidinium hydrogen (+)-l-tartrate monohydrate—A new organic NLO crystal

A new organic NLO material N,N′-diphenylguanidinium hydrogen (+)-l-tartrate monohydrate (DPGTM) single crystal was grown by a slow evaporation technique using aqueous ethanol solution. X-ray diffraction was carried out to confirm the cell parameters and crystalline nature of DPGTM crystal. The presence of various functional groups was identified by FT-IR spectrum. UV – vis spectral study reveals that the DPGTM crystal is optically transparent in the wavelength region 200 – 800 nm. The optical parameters, such as optical band gap, extinction coefficient (k) and refractive index (n) were determined from the transmittance data. The dielectric behavior of DPGTM crystal was analyzed and the real and imaginary parts of optical dielectric constant were determined. The laser induced surface damage threshold study was carried out for the grown crystal using Nd:YAG laser. The second harmonic generation (SHG) of the grown crystal was measured by the Kurtz and Perry powder technique and was found to be comparable with that of the standard reference material potassium dihydrogen phosphate (KDP) crystal.