Preferred Label : first-order phase transition;
IUPAC definition : A transition in which the molar Gibbs energies or molar Helmholtz energies of the
two phases (or chemical potentials of all components in the two phases) are equal
at the transition temperature, but their first derivatives with respect to temperature
and pressure (for example, specific enthalpy of transition and specific volume) are
discontinuous at the transition point, as for two dissimilar phases that coexist and
that can be transformed into one another by a change in a field variable such as pressure,
temperature, magnetic or electric field. Example: The transition on heating CsCl to
752 K at which it changes from the low-temperature, CsCl-type structure to the high-temperature
NaCl-type structure. Synonymous with discontinuous phase transition.;
Origin ID : F02390;
Automatic exact mappings (from CISMeF team)
- See also
A transition in which the molar Gibbs energies or molar Helmholtz energies of the
two phases (or chemical potentials of all components in the two phases) are equal
at the transition temperature, but their first derivatives with respect to temperature
and pressure (for example, specific enthalpy of transition and specific volume) are
discontinuous at the transition point, as for two dissimilar phases that coexist and
that can be transformed into one another by a change in a field variable such as pressure,
temperature, magnetic or electric field. Example: The transition on heating CsCl to
752 K at which it changes from the low-temperature, CsCl-type structure to the high-temperature
NaCl-type structure. Synonymous with discontinuous phase transition.
