Thermodynamic Phenomena in Glass

Abstract

Whatever method – mechanical, thermal or chemical – we use, microstructuring of glasses is always intrusive, which means bonds between anions and cations are being broken, and this requires energy. The actual energy required for the process of microstructuring has to exceed the theoretical binding energy and must also cover the needs for the applied process conditions and losses. Section 1.1 describes the ionic arrangement and structure of glasses. The presence of short-range order, as represented in the structure coordination tetrahedra, but absence of long-range ordering, which results in the random arrangement of the coordination polyhedra in the glassy network, makes it rather difficult to formulate generally valid statements about energetic phenomena in glasses. If we indeed want to define a certain value for the binding energy even for a glass with a well-defined composition, we have to consider that this would only represent a mean value with a wide distribution.