IN ONE-STEP FROM KCL TO YBA2CU3O7 CRYSTAL-GROWTH - UNDERSTANDING OF DENDRITIC MORPHOLOGY IN CRYSTALS

A dendritic morphology of crystals is often encountered in nature and seems to be a universal structure for systems grown from supersaturate d solutions such as KCl or NaCl. The observation of similar dendrites in bulk superconducting YBa2Cu3O7 covalent material leads us to correl ate the cases. From a simple new kinetics mechanism, the understanding of such a crystal-growth peculiarity is discussed. The kinetic mechan ism condition for the occurrence of dendritic shapes of growing crysta ls from multiphase systems is given through a relationship between the velocity of the growth front and classical thermodynamical quantities . Some simulated systems illustrate the observed features.