Fractals on Surface Patterns of KBr Solution Growth

The growth patterns on the {100} surface of KBr crystal, growing in aqueous solution at low supersaturation (sigma = 1.0%), were observed in situ with an optical microscope. Some growth steps appeared at the crystal edges and then advanced toward the center of the {100} surface. The growth steps were bunched and formed lines. They appeared as a complex growth pattern on the growing surface. The complexity of the growth step patterns increased with crystal growth, while the advance rate of the growth steps decreased with it. The complexity was represented as a fractal. The fractal dimension of the growth step patterns was calculated to be 0.87-1.27 during the observation.