Colloidal crystals are known as a particle system which forms ordered arrays in deionized water. Colloidal crystals offer an important opportunity to study the dynamics of crystallization. In atomic or molecular fluids, the rate of attachment of particles to a growing interface is the order of picoseconds, whereas in a colloidal system it corresponds to the rate of diffusion of particles in the order of seconds. This slows growth rates significantly and allows detailed mechanism of nucleation and growth of crystals to be studied on a convenient timescale. We aimed to clarify the effects of microgravity on nucleation and growth processes using colloidal crystals as a model material. The merit of studying colloidal crystals lies in in-situ observation of growth dynamics with visible light. Using reflection spectrum method, lattice constants Do were determined based on the Bragg reflection. The intensity measurements of Bragg reflections were executed to evaluate the appearance of small nucleates during the crystal growth under low-gravity. Light scattering methods were also applied to low-gravity experiments. Low-angle light scattering method and dynamic light scattering method were used to measure the size of grown crystallites and to evaluate diffusion coefficients of latex particles during the formation of colloidal crystals, respectively. Low-gravity experiments were executed during parabolic flights of MU-300 rear-jet airplane.
