Transitions and Collective Phenomena in Solids. New Properties

Abstract

Melting and sublimation of a solid are two important phase transitions, but they are not the only changes of state in solids. Indeed, the appearance of a magnetic phase in a nonmagnetic solid when its temperature is reduced below a certain point (called the Curie temperature) is another type of important phase transition (paramagnetic/ferromagnetic transition), investigated in particular by P. Curie and P. Weiss. The transition from a conducting to a superconducting state (superconductivity) and ferromagnetism reflect the appearance of new properties of the solid state, implying electron coupling.