Surface crystallization of leucite in glasses

Abstract The aim of this paper was to study surface crystallization of leucite in glasses derived from an SiO 2 -Al 2 O 3 -K 2 O base glass in a comparative study with another glass based on SiO 2 -Al 2 O 3 -MgO. Monolithic samples and glass powder of SiO 2 -Al 2 O 3 -K 2 O glass were studied and phase formations were determined by using scanning electron microscopy. Heterogeneous nucleation was promoted by seeding the surface of the monolithic glass samples with glass dust to produce a highly disordered crystal as the primary phase. In addition to leucite formation, growth of a highly symmetric, flat, almost two-dimensional crystal phase with controlled diffusion was also observed. In glass granules, leucite demonstrated rapid, almost dendritic growth, from the nucleating centers. Use of leucite ceramic as a restorative dental product is considered.