Glass crystallization and interfaces

Glass-crystalline interfaces in oxide ceramics have been investigated using several novel approaches. Continuous silicate-glass films of controlled thickness and known composition have been introduced onto monocrystalline substrates of α-Al2O3 and MgO. The substrate-film geometry has been subjected to different heat treatments; to induce crystallization of the glass and to study behavior of alumina surfaces in contact with molten glass. Epitactic crystallization of glass films emphasizes the influence of substrate-crystallography during devitrification. The dewetting behavior of the glass is affected by the thickness of the glass layers in addition to the faceting of alumina surfaces. Initial stages of a silicate liquid infiltrating the grain boundaries of MgO have also been studied.