Hardness, Tougheness, And Scratchability Of Germanium-Selenium Chalcogenide Glasses

Ge-Se Chalcogenide glasses are characterized by relatively low hardness and low fracture toughness. Actually, the hardness of chalcogenide glasses is low enough so that the brittleness parameter, B=H/K, is lower than that of silicate glasses. Whereas hardness and Young's modulus increase with increasing germanium contents, fracture toughness follows a trend similar to that of the density and exhibits a maximum for the Ge20Se80 composition, which corresponds to the rigidity percolation threshold.