Studies on nucleation kinetics and growth aspects of solution grown nonlinear optical single crystal: 2-carboxypyridinium maleate (2-CM)

Abstract

The nature of understanding the crystallization phenomenon with the controlled mechanism and desired properties are still under lots of investigation. Effective conditioning with necessary separation and purification process are important in many chemical, pharmaceutical, petrochemical and electronics industries. The growth phenomenon majorly relies on the kinetics of nucleation and rates of supersaturation of the developing medium. Therefore, it becomes inevitable to understand the nucleation thermodynamical qualities and completely regulating crystallization parameters for effective production of crystal in a large manner. The foundational parameters of 2-CM such as solubility and metastable zonewidth were determined experimentally using gravimetric and polythermal methods, respectively. The experimentally determined induction period was investigated for different ratios, which confirmed that growth phenomenon depends on the supersaturation of the growth medium. Experimental data obtained from induction period was used to calculate interfacial tension (γ) of the growth solution. The other nucleation parameters such as energy change per unit volume (ΔGv), critical free energy change of the nucleus (ΔG*), radius of critical nuclei (r*), nucleation rate (J) and also number of molecules in the critical nucleus (i*) were calculated using different aspects of classical theory of homogenous nucleation. The obtained parameters were used for optimizing the growth condition of the medium for having bulk quality single crystals. The designated parameters are discussed in detail.