10. Relation Between the Density Changes and Thermal Expansion Anomalies in the Amorphous Metallic Alloys

The structural relaxation of bulk samples of the amorphous metals with Pd₄₀Cu₃₀Ni₁₀P₂₀ bulk glassy alloy as an example, by the determination of the temperature dependences of the thermal expansion at a constant heating rate of 10 K/min and isothermal measurement of the density changes, has been studied. An expression for the theoretical description of density changes of amorphous metallic alloys as a function of the heat treatment conditions in the framework of the free volume model (FVM) has been derived. Experimental determination of the density changes of a Pd₄₀Cu₃₀Ni₁₀P₂₀ glassy alloy is carried out. A good agreement between the experimental data and the FVM theoretical expectations is established. Calculated using the derived theoretical description via inserting in it the experimentally obtained thermal expansion, experimental data have been carried out. They are in good agreement with the experimental data for the density changes of the same system.