The reduction of rare-earth metal halides with unlike metals - Wohler's metallothermic reduction

Rare-earth halides may be reduced by rare-earth metals (conproportionation) and, as an alternative, by unlike metals such as alkali or alkaline-earth metals, a route first established for the production of rare-earth metals. It has great power for exploratory research subject to enhanced reactivity at lower temperatures and the formation of alkali halide flux for crystal growth. A large number of new compounds, ternary and higher, salt-like and (semi-)-metallic including interstitially stabilized cluster compounds has been synthesized and characterized during the last decades.