Photoinduced Fluidity and Viscoelasticity in Chalcogenide Glasses

This work is an attempt to apply conventional mechanical testing to characterize the photoinduced viscoelastic behavior of chalcogenide glasses. Creep or relaxation‐recovery experiments are usually performed to characterize the delayed elastic contribution to deformation, during thermally activated flow. In this article, relaxation‐recovery is used to characterize delayed elasticity under irradiation condition and to investigate the influence of the photon irradiation on the viscoelastic behavior. It is showed that thermally activated processes and photoinduced ones are decoupled. The viscoplastic deformation under irradiation is the sum of thermally activated and photoinduced processes. As soon as the irradiation ceases, chalcogenide glasses behave exactly as if they had never been irradiated. The photoinduced viscoelastic behavior seems to be solely due to transient photoinduced structural defects.