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

Abstract

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 Ba,InO,F, Ba,InO,Cl and Ba,InO,Br all crystallize in the space group P4/nrnm and exhibit complete oxide halide segregation, producing alternating sections of halide [ BaF] and oxide [ BaO] ions separating infinite InO, layers. However, Ba,ScO,F 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/mrnm. 19F MAS NMR data have been collected from Ba,InO,F and Ba,Sc03F, and confirm the structural analysis in terms of a single type of fluoride ion site in each material.The structural chemistry of complex oxide halides has become the subject of renewed interest following the recent reports of high-temperature superconductivity in various layered oxide halide cuprates. There appear to be at least three routes to these p-type oxide halide superconductors: interstitial halogen doping, cation substitution and anion substitution. Interstitial fluorine doping of Sr,CuO, affords the 46 K superconductor Sr,CuO,F,+,,' in which the fluoride ions occupy solely the apical sites about the copper, giving effective CuO, square planes and an interstitial site in the new SrF rocksalt layer.

A New 2+/3+ Perovskite: The Synthesis and Structure of BaScO2F

“…Derived bond lengths were 12 ; Ba-O/F 2.9847(2) and 6;Sc-O/F 2.0850(2) A s . F MASNMR data were collected on a Chemagnetics CMX-200 spectrometer operating at 188.288 MHz for fluorine nuclei as described previously (9). Chemical shifts were referenced by replacement to the signal of CFCl or C F .…”

Efficient Bi-Functional Electrocatalysts of Strontium Iron Oxy-Halides for Oxygen Evolution and Reduction Reactions in Alkaline Media

“…50 and PbBr 2 ; these were intimately mixed and heated in alumina crucibles at 550 • C for 12 h. The sample was then pelletized under ∼8 ton cm −2 and reacted for 24 h at 650 • C. The phase purity of all product powders was confirmed post synthesis using a Siemens D5000 diffractometer operating with Cu K α1 radiation. [50][51][52][53] Additional powder X-ray diffraction patterns shown in Fig. 1 Electrochemical characterization.-Electrochemical measurements were performed in a three-electrode one-compartment cell, with a 2.0 mm polished diameter Au as working electrode, a platinum (1.0 cm 2 foil) and saturated calomel as counter and reference electrode, respectively.…”

Влияние природы галогена на локальную структуру и интеркалацию воды в оксигалогенидах Ba-=SUB=-2-=/SUB=-InO-=SUB=-3-=/SUB=-X (X = F, Cl, Br)

“…Согласно более ранним исследованиям [10,11] Для определения возможности диссоциативного по-глощения воды из газовой фазы для предварительно гидратированных образцов были проведены термические и масс-спектрометрические исследования. Для всех ис-следуемых образцов потеря массы составила ∼ 0.9 mol на формульную единицу вещества.…”