Impact of Maxwell rigidity transitions on resistance drift phenomena in GexTe1−x glasses

Abstract

Amorphous chalcogenides usually exhibit a resistivity, which increases with age following a power law ρ ∼ tα. Existing theories link this change in amorphous state resistivity to structural relaxation. Here, the impact of fundamental glass properties on resistance drift phenomena in amorphous GexTe1−x networks is studied. Employing Raman spectroscopy, the Maxwell rigidity transition from flexible to stressed rigid is determined to occur in the compositional range 0.250 < xc < 0.265. Stressed rigid glasses (x > 0.265) exhibit rather strong resistance drift, where the drift parameters increase steadily from α = 0.13 for amorphous GeTe to α = 0.29 for compositions near the stiffness threshold xc. On the other hand, the drift parameter in flexible glasses (x < 0.25) decreases with decreasing Ge content x to values as low as α = 0.05. These findings illustrate the strong impact of the stiffness threshold on resistance drift phenomena in chalcogenides.