Influence of solute-solvent interactions at the crystal-solution interface on the growth and morphology of the nonlinear optical single crystal methyl-p-hydroxybenzoate (p-MHB)

Abstract

• Solute-solvent interactions at different crystal faces of p -MHB were investigated. • Effect of solvent polarity on growth and morphology p -MHB crystal was revealed. • Solubility and nucleation time from solution with different solvents were studied. • Large dimensional optical quality monoclinic p -MHB single crystal was grown. • Morphological importance of different growth faces of p -MHB crystal was revealed. The influence of solute-solvent interactions was realized at the crystal-solution interface on the end crystal morphology of the nonlinear optical monoclinic methyl- p -hydroxybenzoate ( p - MHB) single crystal when growing from solutions with solvents of different in nature. Polar protic solvents such as methanol and ethanol and polar aprotic solvents such as acetone and ethyl acetate afforded p -MHB single crystals having a prismatic morphology and the nonpolar solvent toluene provided a crystal with columnar morphology. Because of the difference in their polar nature, these solvents show a significant difference in the solute solubility, rate of evaporation, level of supersaturation generated within the solution, time consumed for nucleation and growth rate along different crystallographic directions of the growing crystal. Slow evaporation method was employed for the growth of smaller size p -MHB single crystals from solutions with various solvents and a large dimensional p -MHB single crystal of size 45 × 42 × 62 mm 3 was grown through seeded controlled cooling of the solution method. The results indicate that the nature of hydrogen bonding interactions exists between different crystal faces and the corresponding solvent molecules used in the present study caused a significant change in the end habit and morphology of crystals.