Viscosity measurement in halide melts

Viscosities of three kinds of halide liquids were measured at temperatures near the glass transition and above the melting point. The liquids and glasses investigated were two fluoroaluminates, a cadmium mixed halide, cadmium halide phosphate and gallium-indium fluoride glasses. These glasses were designed for a variety of rare-earth doped fibre amplifiers and lasers. The cadmium mixed halide glass has a strong non-Newtonian behaviour, while near-Newtonian behaviour was observed in fluoroaluminate liquids. The implications of these results on fibre drawing and low-loss fibre fabrication are discussed. Viscosity data were fitted to models and the appropriateness of the fits is discussed.