Unidirectional growth,optical, mechanical and dielectric studies on a novel NLO crystal: l-Arginine 4-nitrophenolate 4-nitrophenol dihydrate

The bulk single crystal of l-arginine 4-nitrophenolate 4-nitrophenol dihydrate (LAPP), an efficient organic NLO material of size 74 mm in length, 18 mm in diameter, was grown successfully by Sankaranarayanan–Ramasamy (SR) method. Single crystal X-ray diffraction study reveals that LAPP crystallizes into monoclinic system with the space group P2₁. The unidirectional growth along the plane (1 1 0) was confirmed from the powder XRD pattern with the sharp peak having maximum intensity. Optical absorption spectrum shows that LAPP has highly transparent in the entire visible and IR region with a wide band gap of 3.9 eV for large photon absorption. Vickers micro hardness measurement was performed to know the mechanical strength of the crystal. Dielectric profile of LAPP at room temperature brings forth low value of dielectric loss and dielectric constant at higher frequencies. Photoluminescence study reveals that LAPP exhibit green emission in the wavelength region 538 nm. The SHG efficiency of the crystal is measured by Kurtz's powder test using Nd:YAG Laser.