Controlled conversion of metal oxyfluorides into superconducting oxides

Abstract

An oxide superconductor article is provided having an oxide superconductor film having a thickness of greater than 0.5 microns disposed on a substrate, said article having a transport critical current density (Jc) of greater than or equal to about 105 A / cm2 at 77K, zero field. The oxide superconductor film is characterized by high Jc and high volume percent of c-axis epitaxial oxide grains, even with thicknesses of up to 1 micron. The oxide superconductor article is prepared by providing a metal oxyfluoride film, said metal oxyfluoride film comprising the constituent metallic elements of an oxide superconductor in substantially stoichiometric proportions; and converting the metal oxyfluoride into the oxide superconductor at a rate of conversion selected by adjusting a reaction parameter selected from the group consisting of temperature, PH2O, PO2, and time and combinations thereof, such that an oxide superconductor film having a transport critical current density of greater than or equal to about 105 A / cm2 at 77K, zero field is obtained.

Description

technical field [0001] The invention relates to a highly oriented oxide superconducting thin film. More specifically, the present invention relates to a method for converting thin films containing metal oxides and metal oxyfluorides into oxide superconducting thin films. Background technique [0002] The discovery of superconducting ceramic oxides has led to enormous efforts to fabricate these oxides into films and coatings with high performance. In general, the formation methods of high temperature superconducting (HTSC) thin films can be divided into two fields: physical methods and chemical methods. [0003] Physical methods include reactive evaporation, manganese sputtering, electron beam deposition, and laser ablation. Although physical deposition methods are capable of forming high-quality films, these deposition methods generally have relatively slow formation rates and require high vacuum environments, resulting in high costs. Furthermore, such techniques are most...

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Problems solved by technology

For example, the MOD method using metal trifluoroacetate was used to prepare thinner (70-80nm) YBa 2 Cu 3 o y (YBCO) film (where the value of y should be sufficient to obtain superconducting properties at a temperature of at least 77K), its Tc>92K, Jc>5×10 6 A / cm 2 (77K, selffield), however it is not possible to use such techniques to prepare much thicker films with similar properties

Indeed, prior to the development of the processing technology described in this patent application, there was no solution based on deposition processing capable of producing high Jc films with a thickness greater than 0.5 microns

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