SOLUTION GROWTH OF VANILLIN SINGLE-CRYSTALS

Single crystals of vanillin were grown by the solution growth method. Vanillin was observed to be very anisotropic, and crystal morphology was strongly dependent on solvent. Crystals grew in needle morphology in pure methanol and ethanol, and in plate morphology in pure chloroform. A mixture of methanol and chloroform was found to be a suitable solvent for crystal growth and crystals up to the size of 7 x 5 x 4 mm3 were grown for optical characterization. Optical quality of crystal was observed to be good. Preliminary studies on frequency conversion showed that vanillin has a higher figure of merit when compared to other crystals suitable for non-linear optical applications in the visible to near-infrared region.