Preparation of a calcium-substituted copper-rich yttrium barium copper oxide superconductor from a spray-dried nitrate precursor

Journal Article · Fri Oct 01 00:00:00 EDT 1993 · Materials Research Bulletin; (United States)

DOI:https://doi.org/10.1016/0025-5408(93)90145-4· OSTI ID:5874375

Gyurov, G; Khristova, I; Peshev, P ^[1]; Abrashev, M V ^[2]

---

1. Bulgarian Academy of Sciences, Sofia (Bulgaria). Inst. of General and Inorganic Chemistry
2. Sofia Univ. (Bulgaria). Faculty of Physics

A calcium-substituted YBa[sub 2]Cu[sub 4]O[sub 8] (1-2-4) high-temperature superconductor is synthesized from a precursor obtained by spray-drying of a nitrate solution containing the corresponding metals in a stoichiometric ratio. The synthesis takes place during one-stage heat-treatment of the precursor at 800 C in an oxygen flow under a pressure of 1 atm within a relatively short period of time, additives as well as intermediate grinding and pressing of the products being not needed. Measurements of the a.c. susceptibility have revealed a very sharp superconducting transition which is comparable with that of samples prepared under a high pressure. The transition in Ca-substituted YBa[sub 2]Cu[sub 4]O[sub 8] occurs at a temperature by about 8 K higher than [Tc] of the Ca-free phase. Raman spectra suggest that during the substitution calcium does not occupy barium positions in the YBa[sub 2]Cu[sub 4]O[sub 8] lattice.

• OSTI ID: 5874375
• Journal Information: Materials Research Bulletin; (United States), Vol. 28:10; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
FABRICATION
CALCIUM OXIDES
COPPER OXIDES
YTTRIUM OXIDES
HIGH-TC SUPERCONDUCTORS
NITRATES
PRECURSOR
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
COPPER COMPOUNDS
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication