Low-temperature synthesis, structure, and stability of Ba{sub 2+y}Cu{sub 3}O{sub 6}

Journal Article · Thu Feb 15 04:00:00 EST 1996 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1996.0099· OSTI ID:263735

Brosha, E L; Garzon, F H; Raistrick, I D ^[1]; Davies, P K ^[2]

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1. Los Alamos National Laboratory, NM (United States)
2. Univ. of Pennsylvania, Philadelphia, PA (United States)

Single-phase powders of Ba{sub 2}Cu{sub 3}O{sub 6} have been prepared at 620{degrees}C under 1 atm of oxygen using freeze-dried nitrate precursors. Calcinations utilizing a precursor with a 1:1 Ba:Cu stoichiometry produced a two-phase mixture of BaO{sub 2} + Ba{sub 2} Cu{sub 3}O{sub 6} and confirmed the stable, oxidized barium cuprate exists with a metal ion ratio close to 2:3. Diffraction studies suggest that Ba{sub 2}Cu{sub 3}O{sub 6}(Ba{sub 0.67}CuO{sub 2}) crystallizes in a structure closely related to the linear chain KCuO{sub 2} and NaCuO{sub 2} cuprates. It is proposed that the reduction of copper and accompanying loss of oxygen observed above 620{degrees}C are accommodated by an increase in the Ba content of the structure and the formation of Ba{sub 2+{gamma}}Cu{sub 3}O{sub 6} with O {le} {gamma} {le} 0.25. Above 710{degrees}C, the high-{gamma} end member is metastable with respect to BaCuO{sub 2}, although it decomposes slowly even at elevated temperatures.

• OSTI ID: 263735
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 122; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM COMPOUNDS
CALCINATION
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
CUPRATES
STABILITY
STOICHIOMETRY