Third order nonlinear studies and other characterization of 4-nitrophenol (4-NP) single crystals

Abstract

The 4-nitro phenol is an organic NLO material. The commercially available 4-nitrophenol was recrystallized in acetone two times to purify the materials. The single crystal of pure 4-nitro phenol (4-NP) compound was grown by slow evaporation and slow cooling techniques using acetone as a solvent. The grown crystals were subjected to various characterization studies. The powder XRD spectrum of 4-NP shows the good crystalline nature of the grown crystal. The lattice parameter values of the grown 4-NP crystals were calculated from single crystal XRD data as a=6.09Å, b=8.79 Å, c=11.61 Å, α=γ=90°, β=103.15. 4-NP crystallizes in monoclinic crystal system with the space group of P21/c. The crystals obtained by slow evaporation technique were subjected to FTIR spectrum. The resultant FTIR spectrum confirms the various functional groups present in 4-NP. The Vis-IR spectrum of 4-NP shows the cut off wave length of 403nm. The differential thermal analysis of 4-NP shows that the melting point of the compound is 115°C. As it crystallizes in centro symmetric space group, it is suitable for third harmonic generation. The nonlinear absorption coefficient (β) and non linear refractive index (n2) were calculated as β=5.03859×10−6 cm/W and n2=1.45967×10−11cm2/W respectively by using Z-scan technique.