Structural Relaxation of Pd₃₉Ni₁₀Cu₃₀P₂₁ Bulk Metallic Glass Under High Pressure

The Pd₃₉Ni₁₀Cu₃₀P₂₁ bulk metallic glass is isothermally relaxed under various pressures. The degree of the structural relaxation is evaluated in terms of the enthalpy recovery behaviours involved in the irreversible glass transition processes by using a temperature-modulated differential scanning calarimetry technique. A roughly linear increase of the recovery enthalpy is observed within the experimental pressure range from 2.67 to 4.45 GPa, which reflects the release of the frozen-in enthalpy in the as-quenched glass with increasing relaxation pressure. The pressure dependence of the time scale of the enthalpy recovery processes is also exhibited.