The crystal growth behaviour of the organic non-linear optical material 2-(α-methylbenzylamino)-5-nitropyridine (MBANP)

Observation of the growth behaviour and measurement of the growth kinetics of 2-(α-methylbenzylamino)-5-nitropyridine (MBANP) has revealed a strong and anomalous dependence of growth rate on supersaturation. At relative supersaturations less than 0.08, slow growing irregular faces were formed. At supersaturations below 0.24 no growth was observed in either 〈010〉 direction. Above this, rapid, but highly imperfect, growth occurred in one 〈010〉 direction while the opposite end of the crystal exhibited zero growth rate at all achievable supersaturations. The factors potentially responsible for this behaviour are discussed. On the basis of these observations, techniques have been developed for the preparation of large (up to 7 x 4 x 3 cm 3 ) high quality single crystals suitable for detailed optical studies and for device fabrication.