An investigation of nucleation and crystallisation phenomena in lithia-alumina-silica glasses

Abstract

An outline of the use of titanium in glass ceramic production is given. To investigate the role of titanium in this process a variety of procedures were necessary. These included X-ray diffraction, Electron microscopy, Optical measurements and Electron spin resonance. Two main approaches to the investigation have been adopted, the first is through the observation of the effects of crystallisation on gadolinium introduced into the glass matrix. The interpretation of the electron spin resonance for gadolinium in terms of a spin hamiltonian has led to the suggestion of two sites for this rare-earth ion. A crystal growth inhibition has been found to be produced by the incorporation of gadolinium in the lithia alumina silica glass ceramics. The alternative method of investigation is concerned with X-ray?. induced defects and the results have been interpreted in terms of local well ordered domains existing within the glass.