Topotactic route for new layered perovskite oxides containing fluorine: Ln1.2Sr1.8Mn2O7F2 (Ln = Pr, Nd, Sm, Eu, and Gd)

A series of fluorine intercalated Ruddlesden–Popper layered perovskites, Ln1.2Sr1.8Mn2O7F2 (Ln = La, Pr, Nd, Sm, Eu, and Gd) were synthesized from the parent oxides, Ln1.2Sr1.8Mn2O7, with the organic reagent, poly(vinylidene fluoride), as the fluorine source. Oxidative intercalation readily occurred by decomposition of the organic fluoride immediately adjacent to the parents.