Browse Prior Art Database

Fabrication of High Temperature Superconducting Films Using Perfluoro-Organometallic Precursors

IP.com Disclosure Number: IPCOM000036728D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Brown, CA: AUTHOR [+4]

Abstract

Preparation of high quality films of superconducting ceramics using solution cast organometallic precursors can be hampered by residual carbon contaminants that concentrate at grain boundaries. These contaminants act to decouple grains leading to broadened superconductivity transitions, low critical currents and poor magnetic field response. These problems are minimized through the use of perfluroalkyl carboxylate and related salts of the metal atom constituents. The perfluoro derivatives, in contrast to the hydrocarbon analogues, decompose by nearly complete volatilization. Further, shorter chain perfluoroalkyls can be used to affect solubility in organic solvents which means less weight loss on decomposition, and, as such, less contraction and cracking.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 73% of the total text.

Page 1 of 1

Fabrication of High Temperature Superconducting Films Using Perfluoro- Organometallic Precursors

Preparation of high quality films of superconducting ceramics using solution cast organometallic precursors can be hampered by residual carbon contaminants that concentrate at grain boundaries. These contaminants act to decouple grains leading to broadened superconductivity transitions, low critical currents and poor magnetic field response. These problems are minimized through the use of perfluroalkyl carboxylate and related salts of the metal atom constituents. The perfluoro derivatives, in contrast to the hydrocarbon analogues, decompose by nearly complete volatilization. Further, shorter chain perfluoroalkyls can be used to affect solubility in organic solvents which means less weight loss on decomposition, and, as such, less contraction and cracking. Other benefits in using such fluorinated organometallic precursors are lower decomposition temperatures, and increased solubility in commonly used coating solvents (alcohols, THF, cellosolve, MEK, etc.)

A specific example of the use of perfluoro-organometallics to prepare high temperature superconducting films is given here: Perfluoracetic acid (CF3COOH) is reacted by metathetical reactions with yttrium nitrate, barium nitrate and copper nitrate, respectively. The solvent and pH are adjusted to effect precipitation of the trifluoroacetate salts. These salts are washed and either reprecipitated or recrystallized to yi...