Ultrasonic relaxation in Zinc-Borate glasses

► Prepared alkali- borate glasses (1 − x) [29Na2O − 4Al2O3 − 67B2O3] − x ZnO. ► Attenuation studied showed well-defined peak shifts toward high temperature and frequency. ► Attributed to thermally activated relaxation governed by the Arrhenius relationship. ► The number of loss centers dependence of the elastic moduli and oxygen density. ► Activation energy and attempt frequency increase with increase the ZnO.