Neutron diffraction study of the antiferromagnetic oxyhalides Sr3Fe2O5Cl2, Sr3Fe2O5Br2 and Sr3FeCoO5Cl2

Synthesis, crystal structure, and properties of novel perovskite oxychalcogenides, Ca2CuFeO3Ch (Ch=S, Se)

“…Our results confirm that the chemistry of layered perovskite oxide chalcogenides and pnictides is indeed not restricted to compounds of Sr and Ba, and calcium appears to be, at least within some structure types, just their smaller analog akin to the oxide halide family [8].…”

“…For instance, the structures of the most promising superconductors, i.e. Ln(O,F)FeAs [1], Sr 2 VFeO 3 As [3], and Sr 3 Sc 2 Fe 2 O 5 As 2 [4], are, in fact, the "filled-up" versions of the LnOCl (PbFCl) [6], Ca 2 FeO 3 Cl [7], and Sr 3 Fe 2 O 5 Cl 2 [7,8] (Fig. 1).…”

“…Thus oxyhalides may prove to be a good source of new charge reservoirs, both for new oxychalcogenides and oxypnictides. Even a cursory survey of the oxide halide family shows that whereas Ca 2+ is a typical constituent of perovskite blocks therein (mostly together with Cu 2+ or Fe 3+ at the B-site [8][9][10]), this alkaline earth cation had not yet been used to contribute to the chalcogenides. Two series of calcium-containing superconducting oxypnictides, Ca n+1 (Sc,Ti) n O 3n-1 Fe 2 As 2 [11] and Ca n+1 (Mg,Ti) n OFe 2 As 2 [12,13], have been prepared recently, but most promising structure types, Hor [15].…”

Magnetic and electronic properties of CaFeO2Cl

“…Neutron scattering experiments revealed antiferromagnetic ordering with magnetic moments orientated parallel to the layers, e.g. G-type antiferromagnetism in Sr 3 Fe 2 O 5 Cl 2 [18]. Belonging to this class of layered transition metal halides, monoclinic CaFeO 2 Cl [19,20] is exceptional because the structure contains no octahedra but consists of layers of edge-sharing FeO 2/2 O 3/3 square pyramids separated by CaCl sheets; no Fe-Cl contacts occur (Fig.…”

Ca4Fe3−Mn O8−Cl2: A new n=3 Ruddlesden–Popper oxychloride

“…Up to now, two manganese-containing oxyhalides have been prepared: Sr 2 MnO 3 Cl, Sr 4 Mn 3 O 7.56 Cl 2 [13,14], with the formal valence states $ 3+ . In addition to manganites, only a few transition metal RP oxyhalides in a single valence state (Cu 2 + , Co 2 + , Co 3 + or Fe 3 + ) are reported [15][16][17][18][19][20][21][22][23]. We successfully synthesized by the flux method, a new series of RP-Mn-oxychloride single crystals: in a ratio of 4:x:3À x (0rx r3; 0.1-0.2 g of the precursor and 2-3 g CaCl 2 -2H 2 O (Aldrich, 499.0%) was placed in a 5 mL Al 2 O 3 crucible.…”