Growth and morphology of the nonlinear optical crystal 3-methoxy-4-hydroxy-benzaldehyde (MHBA)

3-methoxy-4-hydroxy-benzaldehyde (MHBA) is one of the new organic materials that has become important for nonlinear optics (NLO) in recent years because of its large second order nonlinear optical susceptibility and good blue transparency. Single crystals of MHBA were grown by a modified solution growth method. A study has been performed to select a suitable solvent for the growth of this material and to determine the effects of the solvent on the morphology of the crystals. These solvents were first studied to see their effects on the characteristic morphology of the material. From the results of morphology studies, methanol, ethanol, and MEK were selected as possible solvents for the growth. The solubility of MHBA was measured as a function of temperature in each solvent. From the solubility data, we discovered that a mixture of methanol to water (1:1) showed the most promise as a solvent for the growth of MHBA from solution. Crystals were grown using the three solvents in an effort to confirm the results of the solubility test. The properties of the material were studied using Differential Scanning Calorimetry (DSC), Vicker's hardness, and optical absorption spectrum. The results of the above measurements are described in this paper.