Structure of Sb Ge40-Se60 glasses around 2.67 average coordination number

Abstract The evolution of the structure of Sb x Ge 40- x Se 60 ( x = 8, 12, 15, 18 and 20) chalcogenide glasses is determined by high resolution X-ray photoelectron spectroscopy as Sb is added and the average coordination number ( Z ) is varied from 2.60 to 2.72. For glasses with Z Z ≥ 2.67 leads to a strengthening of the above regularity and formation of the structure by shared pyramids and tetrahedra with two or more Se atoms substituted by cations. At the same time Se–Se dimers are present in all the investigated compositions while they are not expected in these Se-deficient glasses. Their formation dictates that there must be metal-rich regions somewhere in the structure.