The thermodynamics of amorphous phases in immiscible systems: The example of sputter-deposited Nb–Cu alloys

摘要: Amorphous metallic alloys, frequently observed to occur in systems with large negative heats of mixing, are much less common which immiscible the equilibrium solid state, such as Nb–Cu. However, amorphous Nb–Cu alloys can be produced over a wide composition range by sputtering. Using isothermal and nonisothermal differential scanning calorimetry, both kinetics thermodynamics these were characterized quantitatively. It was found that formation enthalpies amounted only 4.5–7.6 kJ/g atom. These data combined modeling thermodynamic functions system. The unexpected low Gibbs energies phase demonstrate stabilization liquid develops undercooling. This is connected change sign heat mixing phase, positive at high temperatures temperatures.