Preparation of monosized, spherical, colloidal particles of yttrium barium cuprate superconducting oxide ceramic precursors

1989 ◽  
Vol 8 (2) ◽  
pp. 171-172 ◽  
Author(s):  
Paul M. Kayima ◽  
Syed Qutubuddin
Keyword(s):  
Colloidal Particles ◽  
Oxide Ceramic ◽  
Yttrium Barium Cuprate ◽  
Ceramic Precursors ◽  
Yttrium Barium

Heterogeneous Nucleation of Ordered Mesoporous Materials

1994 ◽  
Vol 371 ◽  
Author(s):  
Jun Liu ◽  
Jud W. Virden ◽  
Anthony Y. Kim ◽  
Bruce C. Bunker
Keyword(s):  
Mesoporous Materials ◽  
Heterogeneous Nucleation ◽  
Colloidal Particles ◽  
Co Adsorption ◽  
Surfactant Solution ◽  
Nucleation Process ◽  
Ordered Mesoporous Materials ◽  
Ordered Mesoporous ◽  
Ceramic Precursors ◽  
Heterogenous Nucleation

AbstractRecently we proposed that heterogenous nucleation is an important phenomenon for the preparation of ordered mesoporous materials. In this paper we further investigate the effect of colloidal particles on the nucleation process of mesoporous materials. Based on the change of the electrical mobilities of the particles in the surfactant solution, we suggest that the adsorption and co-adsorption of surfactant and ceramic precursors changes local structural and chemistry on the particle surfaces, and favors the nucleation events within these regions.

Superconducting fibers from organometallic precursors. Part II: Chemistry and low temperature processing1

1991 ◽  
Vol 6 (5) ◽  
pp. 895-907 ◽  
Author(s):  
Richard M. Laine ◽  
Kay A. Youngdahl ◽  
Richard A. Kennish ◽  
Martin L. Hoppe ◽  
Zhi-Fan Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Organometallic Polymers ◽  
Metal Carboxylate ◽  
Copper Metal ◽  
Metal Carboxylates ◽  
Yttrium Barium Cuprate ◽  
Yttrium Barium ◽  
Organometallic Precursors ◽  
Optimal Approach ◽  
Selection Of

Working principles are developed as guidelines for the selection and/or design of organometallic polymers for processing fiber precursors to metal oxide fibers. These principles form the basis for the selection of metal carboxylate preceramics as an optimal approach to processing yttrium barium cuprate (123) ceramic superconducting fibers. A variety of candidate yttrium, barium, calcium, strontium, bismuth, and copper metal carboxylates were synthesized. Solubility and empirical rheology tests were conducted to screen these compounds to choose spinnable precursor systems. Simple extrusion studies confirmed that THF solutions of mixtures of yttrium, barium, and copper isobutyrates with some quantity of barium 2-ethyl-hexanoates can be used to successfully form 60–70 μm diameter 123 precursor fibers.

ChemInform Abstract: Preparation of Yttrium Barium Cuprate YBa2Cu3O7-δ from Solutions.

ChemInform ◽  
2010 ◽  
Vol 22 (47) ◽  
pp. no-no
Author(s):  
G. N. NOVITSKAYA ◽  
V. S. FLIS ◽  
V. M. PAN ◽  
A. A. FLIS ◽  
S. V. POLYANETSKAYA ◽  
...  
Keyword(s):  
Yttrium Barium Cuprate ◽  
Yttrium Barium

Adsorption of water molecules on yttrium barium cuprate superconductors

2000 ◽  
Vol 45 (9) ◽  
pp. 1147-1153 ◽  
Author(s):  
B. M. Gorelov ◽  
D. V. Morozovskaya ◽  
V. M. Pashkov ◽  
V. A. Sidorchuk
Keyword(s):  
Cuprate Superconductors ◽  
Water Molecules ◽  
Yttrium Barium Cuprate ◽  
Adsorption Of Water ◽  
Yttrium Barium

Direct Process Metal Alkoxides as Ceramic Precursors

1986 ◽  
Vol 73 ◽  
Author(s):  
R. J. Ayen ◽  
J. H. Burk
Keyword(s):  
Surface State ◽  
Great Promise ◽  
Oxide Ceramic ◽  
Metal Alkoxides ◽  
Direct Process ◽  
Precision Casting ◽  
Ceramic Precursors ◽  
Judicious Choice ◽  
Molecular Doping ◽  
Tetraethyl Silicate

ABSTRACTMetal alkoxides have great promise as oxide ceramic precursors. Direct manufacture from the metal and the alcohol permits the production of high purity materials and of those alkoxides which cannot be easily obtained by other routes. Examples which are of great interest to ceramics are the alkoxides of silicon, aluminum, magnesium and yttrium.Currently, only tetraethyl silicate is produced in large volumes by the direct route, employing a catalytic continuously fed process, yielding a distilled product. The reactivity of silicon, aluminum, magnesium and yttrium is governed by the metal surface state and activation and varies with different catalysts and alcohol chain length and branching.The major use of tetraethyl silicate is in partially hydrolyzed form as binder for precision casting molds and zinc-rich primer coatings. Judicious choice of alkoxide ligands allows the manufacture of soluble or liquid Si, Al, Mg, and Y derivatives. These are especially suitable for molecular doping and mixing in the manufacture of yttriastabilized zirconia, mullite, spinel, cordierite and other oxide ceramic precursors.

Interaction of Yttrium–Barium Cuprate with Fluorine

1991 ◽  
Vol 1 (1) ◽  
pp. 30-33 ◽  
Author(s):  
Yuri I. Vesnin ◽  
Vitali V. Lisitsa ◽  
Yuri V. Shubin
Keyword(s):  
Yttrium Barium Cuprate ◽  
Yttrium Barium

Preparation of Yttrium Barium Cuprate Powder by Sol-Gel Method at Low Temperature

1990 ◽  
pp. 169-172
Author(s):  
Hirohiko Murakami ◽  
Seiji Yaegashi ◽  
Junya Nishino ◽  
Yuh Shiohara ◽  
Shoji Tanaka
Keyword(s):  
Low Temperature ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Yttrium Barium Cuprate ◽  
Yttrium Barium

Controlled heterogeneous nucleation of melt-textured YBa2Cu3O6+x by addition of Al2O3 particles

1993 ◽  
Vol 8 (9) ◽  
pp. 2128-2133 ◽  
Author(s):  
Yan L. Chen ◽  
Lijie Zhang ◽  
Helen M. Chan ◽  
Martin P. Harmer
Keyword(s):  
Reaction Layer ◽  
Peritectic Temperature ◽  
Reaction Products ◽  
Yttrium Barium Cuprate ◽  
Alumina Particles ◽  
Nucleation Mechanisms ◽  
Yttrium Barium ◽  
Rich Liquid ◽  
Melt Texturing ◽  
Microstructural Examination

The reaction between alumina and yttrium barium cuprate subjected to a melt-texturing heat treatment was studied. Microstructural examination of quenched, partially transformed samples revealed that at ∼1050 °C (which is above the incongruent melting temperature of YBa2Cu3O6+x) a reaction layer forms at the alumina interface. The reaction products were identified as Ba6Y2Al4O15 and a copper-rich liquid phase. On cooling below the peritectic temperature, aligned domains of YBa2Cu3O6+x (123) were observed to nucleate preferentially at the reaction layer. For samples of melt-textured 123 deliberately seeded with alumina particles, it was found that nucleation and growth of 123 occurred exclusively at the particles. A reaction sequence for the formation of the Ba6Y2Al4O15 is put forward, together with a discussion of the possible nucleation mechanisms for the 123.

Nuclear Reaction Probe of Oxygen Vacancy Migration in Electrically Fatigued PZT Thin Film Capacitors

1994 ◽  
Vol 361 ◽  
Author(s):  
R.L. Pfeffer ◽  
W.D. Wilber
Keyword(s):  
Thin Film ◽  
Lead Zirconate Titanate ◽  
Ferroelectric Thin Film ◽  
Lead Zirconate ◽  
Thin Film Capacitors ◽  
Pzt Thin Film ◽  
Pt Electrodes ◽  
Yttrium Barium Cuprate ◽  
Yttrium Barium ◽  
Accuracy Of Measurement

ABSTRACTThe migration of oxygen vacancies and their entrapment near film-electrode interfaces has been proposed as a cause of fatigue (i.e., polarization weakening) in ferroelectric thin film capacitors. To test this idea, lead zirconate titanate (PZT) thin films were epitaxially deposited by laser ablation on LaAlO3 substrates with yttrium barium cuprate (YBCO) base electrodes. Thin film capacitors were formed by deposition of noble metal (Pt) cap electrodes; half of them were then electrically fatigued by repeated polarization reversals (108 cycles). The distributions of oxygen in the two halves were then compared by means of accelerator-based nuclear backscattering (using the narrow elastic resonance at 3.045 MeV in the scattering of 4He from 16O) throughout the bulk of the PZT films and especially right under the Pt electrodes. We were unable to detect any difference in the oxygen profiles to within the accuracy of measurement, which was about 1 % of the oxygen concentration. Compositional changes, at least involving oxygen, do not seem to be responsible for the striking electrical alterations seen in fatigued PZT.

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