Three phases in the system Hg{sub 1{minus}x}C{sub x}Ba{sub 2}CuO{sub y} (0.00 {le} x {le} 1.00)

Journal Article · Fri Dec 01 04:00:00 EST 1995 · Materials Research Bulletin

DOI:https://doi.org/10.1016/0025-5408(95)00154-9· OSTI ID:175859

Loureiro, S M; Capponi, J J ^[1]; Antipov, E V ^[1]; Marezio, M ^[1]

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1. CNRS-UJF, Grenoble (France). Lab. de Cristallographie

Samples of the [Hg{sub 1{minus}x}C{sub x}]-Ba{sub 2}CuO{sub y} system [(Hg,C)-1201] with stoichiometries within the range 0.00 {le} x {le} 1.00 were synthesized by a high-pressure, high-temperature technique. The sample with x = 0.00 [HgBa{sub 2}CuO{sub 4+{delta}}] was non-superconducting with lattice parameters a = 3,8676(2) {angstrom}, c = 9.470(1) {angstrom}. At low ranges of substitution (0.10 {le} x {le} 0.30), the predominant phase was found to be Hg-1201 with identical lattice parameters to those found for x = 0.00. At x = 0.40 the Hg-1201 phase coexists in similar proportions with the phase of mixed [Hg{sub 1{minus}x}, C{sub x}]-1201 stoichiometry. At x = 0.50, this second phase with lattice parameters a = 3.9271(3) {angstrom}, c = 8.676(2) {angstrom} is predominant and only traces of the Hg-1201 phase were found. At x = 0.75 the [Hg{sub 1{minus}x}, C{sub x}]-1201 phase found for x = 0.50 coexists with the CO{sub 3}Ba{sub 2}CuO{sub y} phase, which is the extreme of the substitution range. This latter was predominant at x = 1.00 with lattice parameters a = 4.0044(3) {angstrom}, c = 7.909(1) {angstrom}, but at higher pressure than the previous substitutions. This system is constituted of three main phases, HgBa{sub 2}CuO{sub 4+{delta}}, Hg{sub 1{minus}x}C{sub x}Ba{sub 2}CuO{sub y} (x {approx} 0.50) and CO{sub 3}Ba{sub 2}CuO{sub y}, which appear in different proportions according to the percentage of substitution and the applied synthesis pressure.

• OSTI ID: 175859
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 12 Vol. 30; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
CARBIDES
COPPER OXIDES
CRYSTAL STRUCTURE
LATTICE PARAMETERS
MERCURY COMPOUNDS
MERCURY OXIDES
PHASE STUDIES
POWDERS
PRESSURE DEPENDENCE
STOICHIOMETRY
SUPERCONDUCTIVITY
SYNTHESIS
TEMPERATURE DEPENDENCE
TIME DEPENDENCE