title: NaFe3(HPO3)2((H,F)PO2OH)6: A Potential Cathode Material and a Novel Ferrimagnet.
abstract: A novel iron fluorophosphite, NaFe3(HPO3)2((H,F)PO2OH)6, was synthesized by a dry low-temperature synthesis route. The phase was shown to be electrochemically active for reversible insertion of Na(+) ions, with an average discharge voltage of 2.5 V and an experimental capacity at low rates of up to 90 mAhg(-1). Simple synthesis, low-cost materials, excellent capacity retention, and efficiency suggest this class of material is competitive with similar oxyanion-based compounds as a cathode material for Na batteries. The characterization of physical properties by means of magnetization, specific heat, and electron spin resonance measurements confirms the presence of two magnetically nonequivalent Fe(3+) sites. The compound orders magnetically at TC ≈ 9.4 K into a state with spontaneous magnetization.
authors.affiliation: School of Chemistry, University of St. Andrews , St. Andrews, Fife KY16 9ST, U.K.
authors.forename: Irene
authors.initials: I
authors.lastname: Munaò
authors.affiliation: Faculty of Physics, Moscow State University , Moscow 119991, Russia.
authors.forename: Elena A
authors.initials: EA
authors.lastname: Zvereva
authors.affiliation: Faculty of Physics, Moscow State University , Moscow 119991, Russia.|Theoretical Physics and Applied Mathematics Department, Ural Federal University , Ekaterinburg 620002, Russia.|National University of Science and Technology "MISiS" , Moscow 119049, Russia.
authors.forename: Olga S
authors.initials: OS
authors.lastname: Volkova
authors.affiliation: Faculty of Physics, Moscow State University , Moscow 119991, Russia.|Theoretical Physics and Applied Mathematics Department, Ural Federal University , Ekaterinburg 620002, Russia.|National University of Science and Technology "MISiS" , Moscow 119049, Russia.
authors.forename: Alexander N
authors.initials: AN
authors.lastname: Vasiliev
authors.affiliation: School of Chemistry, University of St. Andrews , St. Andrews, Fife KY16 9ST, U.K.
authors.forename: A Robert
authors.initials: AR
authors.lastname: Armstrong
authors.affiliation: School of Chemistry, University of St. Andrews , St. Andrews, Fife KY16 9ST, U.K.
authors.forename: Philip
authors.initials: P
authors.lastname: Lightfoot