Cationic substitutions in the [open quotes]2201-1201[close quotes] intergrowth HgTl[sub 2]Ba[sub 4]Cu[sub 2]O[sub 10]

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · Chemistry of Materials; (United States)

DOI:https://doi.org/10.1021/cm00046a017· OSTI ID:6768124

Goutenoire, F; Hervieu, M; Martin, C; Maignan, A; Michel, C; Letouze, F; Raveau, B ^[1]

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1. Universite de Caen (France)

The study of the substitution of strontium for barium and of mercury for thallium in the cuprate HgTl[sub 2]Ba[sub 4]Cu[sub 2]O[sub 10] has allowed two solid solutions to be synthesized, HgTl[sub 2]Ba[sub 4-x]Sr[sub x]Cu[sub 2]O[sub 10] with 0 [le] x [le] 1.5 and Hg[sub 1+y]Tl[sub 2-y]Ba[sub 4]Cu[sub 2]O[sub 10+[delta]] with 0 [le] y [le] 0.4. The XRD and HREM studies of these phases confirm that they consist of regular intergrowths of the 1201 (HgBa[sub 2]CuO[sub 4] type) with the 2201 (Tl[sub 2]Ba[sub 2]CuO[sub 6] type) structures and show that barium and strontium are statistically distributed over the two kinds of [AO][infinity] layers (A = Ba, Sr). The investigation of the superconducting properties shows that the as-synthesized phases are overdoped and do not superconduct but can be optimized by annealing in an hydrogenated argon flow. The substitution of thallium by mercury does not modify the superconducting properties; a [Tc] of 50 K is reached for Hg[sub 1.4]Tl[sub 1.6]Ba[sub 4]Cu[sub 2]O[sub 10-[delta]], i.e., close to that observed for HgTl[sub 2]Ba[sub 4]Cu[sub 2]O[sub 10]. On the opposite the substitution of strontium for barium leads to a rapid decrease of [Tc] for HgTl[sub 2]Ba[sub 4-x]Sr[sub x]Cu[sub 2]O[sub 10], from 50 K for x = 0 to 30 K for x = 0.8, and superconductivity vanishes for x > 0.8. 17 refs., 8 figs., 3 tabs.

• OSTI ID: 6768124
• Journal Information: Chemistry of Materials; (United States), Journal Name: Chemistry of Materials; (United States) Vol. 6:10; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CATIONS
CHARGED PARTICLES
COHERENT SCATTERING
COPPER COMPOUNDS
CRITICAL TEMPERATURE
CUPRATES
DIFFRACTION
DISPERSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
HIGH-TC SUPERCONDUCTORS
IONS
MERCURY COMPOUNDS
MICROSCOPY
MIXTURES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SCATTERING
SOLID SOLUTIONS
SOLUTIONS
STRONTIUM COMPOUNDS
SUPERCONDUCTIVITY
SUPERCONDUCTORS
THALLIUM COMPOUNDS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
X-RAY DIFFRACTION