4He glass phase: A model for liquid elements

Highlights: • The glass phase of ⁴He confined in nano-pores under pressure is ultra-stable. • Its frozen enthalpy is 10.5% of the melting heat ΔH_m as expected in liquid elements. • Its latent heat of formation is 9.25% of ΔH_m as predicted. • The 3rd law of thermodynamics reduces the enthalpy and increases T_g. • A residual entropy of the glass phase exists at 0 K. The specific heat of liquid helium confined under pressure in nanoporous material and the formation, in these conditions, of a glass phase accompanied by latent heat are known. These properties are in good agreement with a recent model predicting, in liquid elements, the formation of ultrastable glass having universal thermodynamic properties. The third law of thermodynamics involves that the specific heat decreases at low temperatures and consequently the effective transition temperature of the glass increases up to the temperature where the frozen enthalpy becomes equal to the predicted value. The glass residual entropy is about 23.6% of the melting entropy.