Abstract
Much work has been done on cation substitution of manganese perovskites, but less on anion substitution. Recently there have been reports on fluorination of these compounds, generally leading to double perovskite structures. This work explores the effect of fluorine substitution on the magnetic and electrical properties of the perovskite cubic strontium manganite using first principles DFT calculations. Results on fluorine-doped strontium manganite with one or two fluoride ions surrounding each iron are presented. The ground state of Sr2Mn2O5F is found to be a small band gap spin-biased semiconductor. This is the first proposal that a fluorinated manganite could be a ferromagnetic spin-polarised semiconductor.