Fluorides and Oxide-Fluorides of d-Transition Elements

This chapter deals with the description of the most important structural types of transition-element fluorides and oxide-fluorides, pointing out the relationships occurring between these networks. The peculiar nature of M–F bonds generally leads to outstanding physical behavior, such as ferri- and ferromagnetism, piezoconductivity, multiferroism, F-induced high-critical-temperature superconductivity, high ionic conductivity, and optical properties, and the knowledge of the precise structural characteristics of these phases appears to be essential for a better approach of these properties. Some new elaboration methods are described as far as they provide access to materials with specific features (nanosized particles, etc.) and significantly improved properties.