A type of glass that uses chalcogen (pronounced "
kal-kuh-gen") elements such as sulfur, selenium and tellurium. It has the unique property of being able to interact with both photons and electrons. Used in lenses, optical fibers, the recording layer in optical discs, it is also used in the bit cell of phase change memory. See
GST,
phase change disc,
phase change memory and
programmable metallization cell.