Structural approach of CsCl-modified Ga₂S₃-La₂S₃ glasses

Gallium-lanthanum sulfide glasses have specific interesting physical properties, as semiconductor behavior and good transmission at long wavelengths. The addition of CsCl increases the thermal stability region of the glass making it suitable for many applications in optoelectronics. Ga₂S₃-La₂S₃ glasses modified by 10 to 40% CsCl have been studied by X-ray absorption spectroscopy, at the chlorine K edge and at the gallium K edge at 9 K, in order to get information about the actual structural role of CsCl. The chlorine environment is similar to that in CsCl. The gallium coordination sulfur polyhedra are weakly distorted tetrahedra, identical for all samples. The low temperature measurements shown that the polyhedral corner linkage is also unaltered by the addition of CsCl.