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Key thermophysical properties of phase-change materials include: Melting point (T m), Heat of fusion (ΔH fus), Specific heat (c p) (of solid and liquid phase), Density (ρ) (of solid and liquid phase) and thermal conductivity. Values such as volume change and volumetric heat capacity can be calculated there from.
Latent heat is associated with the change of phase of atmospheric or ocean water, vaporization, condensation, freezing or melting, whereas sensible heat is energy transferred that is evident in change of the temperature of the atmosphere or ocean, or ice, without those phase changes, though it is associated with changes of pressure and volume.
In contrast to viscosity, thermal expansion and heat capacity of amorphous materials show a relatively sudden change at the glass transition temperature [18] which enables accurate detection using differential scanning calorimetry measurements. Lev Landau gave a phenomenological theory of second-order phase transitions.
Miscibility gap alloys [35] rely on the phase change of a metallic material (see: latent heat) to store thermal energy. [36] Rather than pumping the liquid metal between tanks as in a molten-salt system, the metal is encapsulated in another metallic material that it cannot alloy with . Depending on the two materials selected (the phase changing ...
Table of specific heat capacities at 25 °C (298 K) unless otherwise noted. [citation needed] Notable minima and maxima are shown in maroon. Substance Phase Isobaric mass heat capacity c P J⋅g −1 ⋅K −1 Molar heat capacity, C P,m and C V,m J⋅mol −1 ⋅K −1 Isobaric volumetric heat capacity C P,v J⋅cm −3 ⋅K −1 Isochoric ...
GeSbTe (germanium-antimony-tellurium or GST) is a phase-change material from the group of chalcogenide glasses used in rewritable optical discs and phase-change memory applications. Its recrystallization time is 20 nanoseconds, allowing bitrates of up to 35 Mbit /s to be written and direct overwrite capability up to 10 6 cycles.
When the phase change occurs, there is a "thermal arrest"; that is, the temperature stays constant. This is because the matter has more internal energy as a liquid or gas than in the state that it is cooling to. The amount of energy required for a phase change is known as latent heat. The "cooling rate" is the slope of the cooling curve at any ...
A condenser is designed to transfer heat from a working fluid (e.g. water in a steam power plant) to a secondary fluid or the surrounding air. The condenser relies on the efficient heat transfer that occurs during phase changes, in this case during the condensation of a vapor into a liquid. The vapor typically enters the condenser at a ...