Chevrel Phases: Genesis and Developments

Abstract

This chapter summarizes the important role played by Marcel Sergent in the discovery in the Rennes Laboratory of the Chevrel Phases, which stimulated considerable interest in the international solid-state chemistry community, because of their remarkable superconducting properties. After a brief general introduction to this topic, the seminal discoveries associated with these phases between 1970 and 1990 are described. After that their initial synthesis and structural determination was discovered, it was necessary to establish their critical superconducting transition temperature, the critical magnetic field, and the critical current density in wires, single crystals, and thin films. More recently their applications as battery materials, in catalysis, and their thermoelectric properties have been studied and are briefly described. These phases opened up the way not only to a rich solid-state chemistry but also to a rich solution chemistry, which complemented the classical field of transition metal carbonyl clusters. The basic cluster units of the Chevrel Phases continue to be studied in the Rennes Laboratory by the heirs of Marcel Sergent and more widely in the international community.