Influence of complexing agents on properties of YBa{sub 2}Cu{sub 4}O{sub 8} superconductors prepared by the sol-gel method

Journal Article · Thu Feb 01 04:00:00 EST 1996 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1996.0048· OSTI ID:223732

Kareiva, A ^[1]; Bryntse, I ^[2]; Karppinen, M ^[3]

---

1. Vilnius Univ. (Lithuania)
2. Stockholm Univ. (Sweden)
3. Helsinki Univ., Espoo (Finland); and others

A systematic study of sol-gel technique synthesized YBa{sub 2}Cu{sub 4}O{sub 8} (124) is presented using six different complexing agents: ascorbic acid, citric acid, 1,2-ethanediol, poly(vinyl alcohol), succinic acid, and tartaric acid. These complexing agents were found to influence significantly the characteristics of both the precursors and the product superconducting material, in particular the homogeneity. The 124 phase was formed by a solid state reaction at 780{degrees}C in flowing oxygen after decomposition of the organic anions at lower temperature. The dried precursor gels and final products were characterized by thermogravimetry, X-ray powder diffraction, scanning and transmission electron microscopy, and magnetic susceptibility measurements. Syntheses using either 1,2-ethanediol or tartaric acid yielded monophasic YBa{sub 2}Cu{sub 4}O{sub 8} powder, with the highest diamagnetic volume fractions and superconducting transition temperatures (onset) at 79-80 K.

• OSTI ID: 223732
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 121; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM COMPOUNDS
CHEMICAL PREPARATION
CRITICAL TEMPERATURE
CUPRATES
HIGH-TC SUPERCONDUCTORS
MAGNETIC SUSCEPTIBILITY
SCANNING ELECTRON MICROSCOPY
SOL-GEL PROCESS
THERMAL GRAVIMETRIC ANALYSIS
X-RAY DIFFRACTION
YTTRIUM COMPOUNDS