Short-Range Order In Ge-As-Te Glasses

The structure of Te-rich (75-80 at.% Te) and Te-poor (40 at.% Te) Ge-As-Te glasses has been investigated by diffraction and extended X-ray absorption fine structure (EXAFS) measurements. Large scale structural models have been crated by fitting simultaneously diffraction and EXAFS datasets by the reverse Monte Carlo simulation technique. It is found that As-As bonds improve the fit quality int he case of Te-rich glasses while no Ge-Ge bonding is necessary in these compositions. In the Te-poor glasses, Te-Te homopolar bonds are also observed while Ge binds preferentially to Te rather than to As.