Studies on the structural, thermal and optical behaviour of solution grown organic NLO material: 8‐hydroxyquinoline

Abstract

Single crystal of 8-hydroxyquinoline (8HQ) having chemical formula C 9 H 7 NO, an organic nonlinear optical (NLO) material has been successfully grown by slow evaporation solution growth technique at room temperature. The crystal system has been confirmed from the powder X-ray diffraction (PXRD) analysis. The crystalline perfection was evaluated by high resolution X-ray diffractometry (HRXRD). From this analysis we found that the quality of the crystal is quite good. However, a very low angle (tilt angle 14 arc sec) boundary was observed which might be due to entrapping of solvent molecules in the crystal during growth. Its optical behavior has been examined by UV-Vis. analysis, which shows the absence of absorbance between the wavelengths ranging from 400 to 1200 nm. From the thermal analysis it was observed that the material exhibits single sharp weight loss starting at 113°C without any degradation. The laser damage threshold was measured at single shot mode and the SHG behavior has been tested using Nd:YAG laser as a source.

Enhancement of second harmonic generation, optical and dielectric properties inL-asparagine monohydrate single crystals due to an improvement in crystalline perfection by annealing

“…In fact, the value of FWHM of the main peak is quite small at 25 arcseconds, which is not very far from that expected by the plane wave theory of dynamical X-ray diffraction (Batterman & Cole, 1964). In SEST-grown crystals it is quite common to observe such low-angle boundaries, which may be due to entrapment of solvent molecules or impurities during crystal growth; these become trapped in the central regions in the form of defect clusters, which in turn lead to grain boundaries (Vijayan et al, 2006(Vijayan et al, , 2007. The fact that the crystalline perfection is not entirely satisfactory is also indicated by the contrast in the transparency as observed in Fig.…”

Unidirectional growth of l-asparagine monohydrate single crystal: First time observation of NLO nature and other studies of crystalline perfection, optical, mechanical and dielectric properties

“…Such a very low value of FWHM can be obtained only for good quality crystals, which may be grown using suitable additives [24]. In SEST grown crystals it is somewhat common to observe such low angle boundaries, which may be due to entrapment of solvent molecules or impurities during crystal growth and blockage in the central regions in the form of defect clusters, which in turn lead to grain boundaries [25,26]. Fig.…”

Crystal growth and properties of novel organic nonlinear optical crystals of 4-Nitrophenol urea

“…Generally, the organic materials have moderate thermal stability as compared to inorganic materials. It was found by Vijayan et al, [21] that, the 8-hydroxyquinoline crystal is stable up to a temperature of 113 °C. Chen et al, [24] have reported that another NLO crystal, 2,6-diaminopyridinium 4-nitrophenolate 4-nitrophenol starts decomposition at a temperature of 155°C.…”

“…It is also found that higher percentage of transmission was observed, when water was used as the solvent. Vijayan et al, [21] reported that the organic NLO material 8-hydroxyquinoline had a minimal absorption in the wavelength regime 300 to 1200 nm. Absence of absorption in the region between 300 nm and 1200 nm is an advantage, as it is the key requirement for materials having NLO properties [22,23].…”