Nanoscale Inhomogeneities in the Glass Transition of Zr_41.2Ti_13.8Cu_12.5Ni₁₀Be_22.5 Bulk Metallic Glass

By using small-angle x-ray scattering technique, correlation lengths of the density fluctuation are determined for the bulk metallic glass Zr_41.2Ti_13.8Cu_12.5Ni₁₀Be_22.5 around the glass transition temperature T_g. Nanoscale inhomogeneities were found to exist in the supercooled liquid and glass state. The correlation length was found to vary with temperature T in an exponential law δ(T)= δ₀+A₁exp-(T-T_∞)/T₁, where T_∞ is the Vogel temperature, and parameters δ₀, A₁ and T₁ were simulated to be 16.45nm, 1.88×10²⁹nm, and 9.65K, respectively, in the temperature region from T_g to T_g+80K. The correlation length of the density fluctuation obtained by the small-angle x-ray scattering method can be considered as the characteristic length of glass transition.