Chalcogenide glass for low viscosity extrusion and injection molding

The invention is directed to chalcogenide glasses suitable for use in plastics forming processes. The glasses have the general formula YZ, where Y is Ge, As, Sb or a mixture of two or more of the same; Z is S, Se, Te, or a mixture of two or more of the same; and Y and Z are present in amounts (in atomic/element percent) in the range of Y=15-70% and Z=30-85%. The chalcogenide glasses of the invention have a 10,000 poise temperature of 400 ° C. and are resistant to crystallization when processed at high shear rates at their 10,000 poise temperature. The glasses can be used to make, among other items, molded telecommunication elements, lenses and infrared sensing devices.