| Abstract
| - The two-component system cycloheptanol (C7) + cyclooctanol (C8) has been studied by means of thermalanalysis, X-ray powder diffraction, and dielectric spectroscopy. In a first step, the polymorphism of pure C7and C8 has been revised, and new unpublished crystallographic data of the stable phases have been reported.Evidence for the isomorphism relationship between the simple cubic (SC) phases of both of the pure componentshas been seen through the continuous evolution of the lattice parameters, the continuous evolution of thedielectric strength, and the existence of a two-phase equilibrium [SC + L]. Despite the solid polymorphismof the pure components, the SC state has been observed to be the sole mixed solid state between 170 K and[SC + L] equilibrium. To perform a complete thermodynamic analysis, measurements of the excess enthalpyin the liquid state were undertaken. These measurements together with the experimental melting-phase diagramallow us to determine the excess thermodynamic properties of the mixed SC state via a compensation law.Dielectric data have been used to interpret the excess properties, and the existence of short-range orientatonalorder for the mixed SC state has been inferred. In addition, this OD mixed state has been classified asextraordinary in light of the log TC−log Tm plot.
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