Anelastic spectroscopy in potassium aluminum metaphosphate glasses

Anelastic spectroscopy (internal friction and the dynamic modulus) was measured by means of a torsion pendulum at 3–12 Hz, in the range of 100–300 K, for a KAP metaphosphate glass. Two thermally activated internal friction peaks appeared at ∼190 and ∼250 K. These peaks were attributed to the behavior of potassium ions (high temperature) and to hydrogen (low temperature). Dynamic modulus showed a gradual decrease with increasing temperature in the range studied for all compositions.