Heating rate dependence of T_g and T_x in Zr-based BMGs with characteristic structures

Heating rate dependence of glass transition and crystallization temperatures is applicable for evaluation of glass structural stability and also for discussion on the apparent activation energies for glass transition and crystallization. The glass-structure stabilities of the Zr-based BMGs (Zr₅₀Cu₄₀Al₁₀, Zr₇₀Cu₂₀Al₁₀ and Zr₇₀Ni₂₀Al₁₀) and the conventional amorphous alloys (Zr₇₀Cu₃₀ and Zr₇₀Ni₃₀) are assessed by the densely packed glass structure as well as the complicated crystallization process. By the reverse Monte Carlo (RMC) simulation with X-ray and neutron diffraction data, it is shown that the densely packed structure is built by icosahedron-like clusters. In Zr₆₅Al_7.5Ni₁₀Pd_17.5 and Zr₆₅Al_7.5Ni₁₀Cu_17.5, the effect of Pd atoms on the glass structure is also described.