Experimental evidence of Snoek-like relaxation in annealed metallic glass

The frequency dependence of the internal friction (IF) of annealed Co-based metallic glass (MG) has been measured at elevated temperatures in the frequency range of 10⁻³≤f≤10³ Hz. It has been found that the IF increases with frequency decrease at a constant temperature. To explain this observation, an analytical model of IF due to anelastic relaxation in a symmetrical two-well potential has been proposed. The model shows that the IF rise with decreasing frequency observed in the experiment can be interpreted as a high frequency tail of a Snoek-like relaxation with distributed activation energies in deep relaxation centers of annealed glassy structure.