Characteristic of dynamic mechanical relaxation processes in Cu₄₆Zr₄₆Al₈ and La_43.4Ce_18.6Ni₂₄Al₁₄ metallic glasses

Dynamic mechanical relaxation processes are very important to understand physical and mechanical properties of metallic glasses. In the current work, dynamic mechanical behaviors of La_43.6Ce_18.4Ni₂₄Al and Cu₄₆Zr₄₆Al₈ metallic glasses were investigated by mechanical spectroscopy. Unlike Cu₄₆Zr₄₆Al₈ metallic glass, La_43.6Ce_18.4Ni₂₄Al₁₄ glassy system shows an evident slow β relaxation process. In addition, physical aging below the glass transition temperature T_g induces a reduction of intensity of the β relaxation. Evolution of the concentration of “defects” of metallic glasses was analyzed in the framework of Interstitialcy theory. Our research provides a new insight on understanding of the correlation between the structural heterogeneity and β relaxation of metallic glasses.