title: Heat capacity anomalies along the critical isotherm in fluid-fluid phase transitions.
abstract: The behavior of the isochoric heat capacity of pure fluids and the isobaric heat capacity at constant composition of binary mixtures along isothermal paths of approach to liquid-gas and liquid-liquid critical points is studied. From the complete scaling formulation of fluid-fluid criticality, explicit expressions for the critical amplitudes of the leading /Y-Y(c)/(-alpha/beta) (where Y can be the density or the mole fraction) contributions are found to reveal previously discovered features of the scaling function, whereas the nature of the most important asymmetry-related terms is characterized. Data for pure toluene and for the binary mixture nitromethane-isobutanol are described within experimental uncertainty using the /Y-Y(c)/(-alpha/beta) singularity plus a linear term. Extensive data for mixtures allow proper visualization of the topological features of the heat capacity-density-temperature surface in the critical region.
authors.affiliation: Departamento de Física Aplicada, Universidad de Vigo, As Lagoas s/n, Ourense 32004, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Losada-Pérez
authors.forename: Germán
authors.initials: G
authors.lastname: Pérez-Sánchez
authors.forename: Jacobo
authors.initials: J
authors.lastname: Troncoso
authors.forename: Claudio A
authors.initials: CA
authors.lastname: Cerdeiriña