Effect of free electron concentration on glass-forming ability of Ca–Mg–Cu system

Intensive studies show that the best glass-forming ability (GFA) is presented as the Fermi surface made contact with pseudo-Brillouin boundaries. Via surveying the GFA of electronic simple Ca–Mg–Cu metallic glass system, we find that the best GFA is presented as the free electrons per atom (e/a) equals to 1.75, which is closed to the value of 1.8 proposed for the ideal amorphous state. The pseudo-gap or minimum in the density of states at the Fermi surface proposed by nearly free electron theory has not been observed in the Ca–Mg–Cu system. Our results indicate that the free electron concentration is an important but not the sole factor for influences in the glass formation.