A new mercury-based superconductor with a [Tc] of 132 K [Hg[sub 0. 5]Tl[sub 0. 5]Ba[sub 2](Ca[sub 1[minus]x]Sr[sub x])[sub 2]Cu[sub 3]O[sub 8+[delta]]]

Journal Article · Thu Sep 01 00:00:00 EDT 1994 · Materials Research Bulletin; (United States)

DOI:https://doi.org/10.1016/0025-5408(94)90056-6· OSTI ID:7018065

Hur, N H; Kim, N H; Lee, K W; Park, Y K; Park, J C ^[1]

---

1. Korea Research inst. of Standards and Science, Taejon (Korea, Republic of)

A new mercury-based superconductor Hg[sub 0.5]Tl[sub 0.5]Ba[sub 2](Ca[sub 1[minus]x]Sr[sub x])[sub 2]Cu[sub 3]O[sub 8+[delta]] (x = 0.14, denoted as Hg,Tl-1223) was prepared by solid state reaction of HgO, Tl[sub 2]O[sub 3], Ba[sub 2]CuO[sub 3+x], and Ca[sub 1[minus]x]Sr[sub x]CuO[sub 2]. X-ray powder diffraction analysis revealed that the Hg,Tl-1223 is isostructural with pristine HgBa[sub 2](Ca[sub 1[minus]x]Sr[sub x])[sub 2]Cu[sub 3]O[sub 8+[delta]]. The crystal symmetry is tetragonal with a space group of P4/mmm, and lattice parameters of a = 3.8649(1) [angstrom] and c = 15.9573(2) [angstrom]. The [Tc] for the as-synthesized sample is about 128 K. After annealing the sample in an argon atmosphere at 400 C for 6 h, the [Tc] has been found to increase to 132 K. In contrast to other mercury-based superconductors, HgBa[sub 2]Ca[sub n[minus]1]Cu[sub n]O[sub 2n+2+[delta]] (n = 1, 2, 3), the Hg,Tl-1223 compound is quite stable even at 500 C in oxygen and argon atmospheres. The Tl substitution at the Hg site appears to stabilize the Hg,Tl-1223 phase and enhance pinning. The critical current density of the Hg,Tl-1223 obtained from the magnetic hysteresis loops is approximately twice larger than that of pristine HgBa[sub 2](Ca[sub 1[minus]x]Sr[sub x])[sub 2]Cu[sub 3]O[sub 8+[delta]].

• OSTI ID: 7018065
• Journal Information: Materials Research Bulletin; (United States), Journal Name: Materials Research Bulletin; (United States) Vol. 29:9; ISSN MRBUAC; ISSN 0025-5408
• 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
BARIUM OXIDES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
MERCURY COMPOUNDS
MERCURY OXIDES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTIVITY
THALLIUM COMPOUNDS
THALLIUM OXIDES
TRANSITION ELEMENT COMPOUNDS