Synthesis, crystal growth and characterization of organic 1,2,4-triazole p-nitrophthalic acid (TPNP) single crystal for nonlinear optical (NLO) applications

Abstract

The novel organic NLO single crystal 1,2,4-Triazole 4-nitrophthalic acid (TPNP) has been synthesised with methanol as a solvent in an equimolar ratio (1:1) by slow evaporation solution technique (SEST). The grown material was characterized for its NLO applications and reported for the first time. TPNP single crystal with the dimension of 10 mm × 5 mm × 4 mm was grown. The grown crystal was analysed through various characterization studies such as structural, optical, thermal, electrical and third harmonic generation (Z-scan) studies. The structural confirmation of the grown TPNP crystals was investigated by Single Crystal X-ray diffraction (SXRD) analysis. The Powder X-ray diffraction (PXRD) was used to identify the (h k l) planes for the purpose of drawing the morphology diagram of the original crystal image. The optical analysis carried out using UV–Vis-NIR study on TPNP crystal showed good optical transparency (80 %) and it can be used for various optical applications. To identify the structure and the functional groups, Fourier transform infrared (FTIR) study was conducted. Thermogravimetric and differential thermal analysis (TG-DTA) revealed the thermal stability of the grown TPNP crystal upto 155 °C. The surface etch pit density of TPNP crystal was carried out using chemical etching analysis. The negative photoconductive nature of title crystal was identified by photoconductivity analysis. The dielectric permittivity and dielectric loss as a function of frequency were measured for grown crystal. Intermolecular interactions and fingerprint plots of TPNP molecules are executed by Hirshfeld surface analysis. LDT of the title crystal was investigated by Q-switched Nd: YAG laser of wavelength 532 nm. Third order NLO parameters and susceptibility were determined using the Z-scan technique. It is concluded that the material can be effectively employed for various optoelectronic and photonic applications.