FORMATION AND MICROSTRUCTURE OF THE GLASSES IN THE SYSTEM Ge-Se-Te.

Bulk samples in the system Ge-Se-Te are prepared by quenching in air from the melt. The glass-forming region and the crystalline phases coexisting with the vitrified phases are investigated by X-ray diffraction method. For the glassy samples, hardness and density are measured, and observation under an electron microscope are carried out. From the present experiments, it can be considered that the structure of the glasses in the system Ge//1//0Se//9//0// minus //xTe//x is constructed from partially cross-linked Se-Te chains with Ge, and that Se in the chain structures is progressively substituted by Te with increasing Te content. The glasses with high Te content in these systems, however, have a remarkable tendency towards phase-separation.