Synthesis and structure of Ba2InO3X (X = F, Cl, Br) and Ba2ScO3F; oxide/halide ordering in K2NiF4-type structures

The structures of three indium and one scandium complex layered oxide halides have been determined from time-of-flight powder neutron diffraction data. The indium phases Ba2InO3F, Ba2InO3Cl and Ba2InO3Br all crystallize in the space group P4/nmm and exhibit complete oxide halide segregation, producing alternating sections of halide [BaF] and oxide [BaO] ions separating infinite InO2 layers. However, Ba2ScO3F shows only partial oxide/fluoride ordering with the fluoride ions occupying the two apical sites on scandium equally with oxide ions, in the space group I4/mwm. 19F MAS NMR data have been collected from Ba2InO3F and Ba2ScO3F, and confirm the structural analysis in terms of a single type of fluoride ion site in each material.

[1]  Y. Zenitani,et al.  Superconductivity in (Ca, Na)2CaCu2O4Cl2 The new simplest double-layer cuprate with apical chlorine , 1995 .

[2]  S. Tanaka,et al.  Superconductivity at 80 K in (Sr,Ca)3Cu2O4+δCl2-y induced by apical oxygen doping , 1995, Nature.

[3]  Z. Hiroi,et al.  Probable hole-doped superconductivity without apical oxygens in (Ca, Na)2CuO2CI2 , 1994, Nature.

[4]  P. Edwards,et al.  Synthesis and superconducting properties of the strontium copper oxy-fluoride Sr2CuO2F2+δ , 1994, Nature.

[5]  H. Müller-Buschbaum,et al.  Über ein weiteres Halogeno-Oxoindat Ba3In2O5Br2 mit Sr3Ti2O7-Struktur , 1992 .

[6]  S. Dann,et al.  The synthesis and structure of Sr2FeO4 , 1991 .

[7]  H. Müller-Buschbaum,et al.  Zur Kenntnis eines Halogenooxo‐Cobaltats(III): Sr8Co6O15Cl4 , 1991 .

[8]  A. Sleight,et al.  New layered copper oxides containing double CuO2 sheets: Ca3Cu2O4Cl2 and Ca3Cu2O4Br2 , 1990 .

[9]  K. Miyauchi,et al.  A new chlorooxocuprate, Ca3Cu2O4Cl2, with an oxygen defect intergrowth , 1990 .

[10]  H. Müller-Buschbaum,et al.  Über ein neues Halogenooxoindat: Ba3In2O5Cl2 mit Sr3Ti2O7‐Struktur , 1990 .

[11]  H. Müller-Buschbaum,et al.  Zur Kristallstruktur von Ba3In2O6 , 1988 .

[12]  H. Müller-Buschbaum,et al.  Ein neues Oxohalogenoferrat: Sr3Fe2O5Cl2† , 1984 .

[13]  C. Michel,et al.  Intercroissance de feuillets “perovskites lacunaires” et de feuillets type chlorure de sodium: Les oxydes La2−xA1+xCu2O6−x2 (A = Ca, Sr) , 1980 .

[14]  H. Müller-Buschbaum,et al.  Über Oxocuprate. XVII. Zur Kenntnis von Ca2CuO2Cl2 und Ca2CuO2Br2 , 1977 .

[15]  F. Galasso,et al.  PREPARATION AND PROPERTIES OF Sr2FeO3F , 1963 .

[16]  F. Galasso,et al.  PREPARATION, STRUCTURE, AND PROPERTIES OF K2NbO3F , 1962 .