Optical spectroscopy, crystalline perfection, etching and mechanical studies on P-nitroaniline (PNA) single crystals

In this work we have presented the bulk growth of P-nitroaniline (PNA) single crystals by slow evaporation solution technique using methanol as a solvent at 300 K. Crystal system and lattice parameters were confirmed by powder X-ray diffraction analysis. Optical absorption and reflectance spectrums were recorded in the wavelength range of 150-3000 nm. Various optical parameters such as transmission (=>57%), optical band gap (=similar to 2.43 eV) were calculated. High-resolution X-ray diffraction study reveals that the grown crystal is having good crystalline perfection as the FWHM was found to be 39 arc s. Etching study was carried on PNA crystal with different etchants and suggests that the grown crystals are of better quality with less dislocation density (=3 x 103). The various mechanical parameters such as hardness, Mayer index, fracture toughness, brittle index were also calculated. (C) 2013 Elsevier B.V. All rights reserved.