Abstract:
Superconductor wires or layers having improved properties and methods for making the same are described. The superconducting layer includes a rare earth element - alkaline earth element - transition metal oxide having an average stacking fault density that is greater than about 0.01 nm -1 , wherein two or more rare earth cations form the rare earth element. To form the superconductor layer of the present invention, a layer having a rare earth element - alkaline earth element - transition metal oxide substantially in a first crystal structure can be provided to a substrate where two or more rare earth cations form the rare earth element. The layer can then be heated at a temperature that is greater than 550 °C under oxidizing conditions to form a high-temperature superconducting layer substantially in a second crystal structure.
Abstract:
Superconductor wires or layers having improved properties and methods for making the same are described. The superconducting layer includes a rare earth element - alkaline earth element - transition metal oxide having an average stacking fault density that is greater than about 0.01 nm -1 , wherein two or more rare earth cations form the rare earth element. To form the superconductor layer of the present invention, a layer having a rare earth element - alkaline earth element - transition metal oxide substantially in a first crystal structure can be provided to a substrate where two or more rare earth cations form the rare earth element. The layer can then be heated at a temperature that is greater than 550 °C under oxidizing conditions to form a high-temperature superconducting layer substantially in a second crystal structure.
Abstract:
The invention relates to a method for producing high temperature superconductors having at least one transformed metal oxide superconducting layer made of an initial material, comprising the following steps: the initial material for the superconducting layer is disposed on a strip-like base, especially a metal strip, and the initial material is transformed into a superconducting layer by controlled heat treatment steps comprising melting and cooling. The invention more specifically relates to the production of coated high-temperature conductors. Foreign elements are introduced in various concentrations, enabling an uneven melt point to be maintained over the cross-section of the strip, enabling specific crystal growth to be triggered, assisted, promoted, maintained and/or controlled during the heat treatment steps, especially during cooling. As opposed to methods known per se, specific crystal growth is initiated, maintained, promoted and controlled for the formation of a mono-crystalline or polycrystalline arrangement in the superconducting layer by means of inward transfer, diffusion or mixing with foreign elements of various concentrations and, consequently, a solid-liquid interface is formed along the cross-section of said strip.
Abstract:
The invention relates to superconductor articles, and compositions and methods for making superconductor articles. The methods can include using a precursor solution having a relatively small concentration of total free acid. The articles can include more than one layer of superconductor material in which at least one layer of superconductor material can be formed by a solution process, such as a solution process involving the use of metalorganic precursors.
Abstract:
This invention relates to a practical superconducting conductor based upon biaxially textured high temperature superconducting coatings. In particular, methods for producing flexible and bend strain-resistant articles and articles produced in accordance therewith are described which provide improved current sharing, lower hysteretic losses under alternating current conditions, enhanced electrical and thermal stability and improved mechanical properties between otherwise isolated films in a coated high temperature superconducting (HTS) wire. Multilayered materials including operational material which is sensitive to bend strain can be constructed, in which the bend strain in the region in which such operational material is located is minimized. The invention also provides a means for splicing coated tape segments and for termination of coated tape stack ups or conductor elements. In one embodiment, a multi-layer high temperature superconductor is provided and includes first and second high temperature superconductor coated elements. Each element includes s substrate, at least one buffer deposited on the substrate, a high temperature superconductor layer, and a cap layer. The first and second high temperature superconductor coated elements are joined at the first and second cap layers.
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 10 A/cm 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 10 A/cm at 77K, zero field is obtained.
Abstract translation:提供具有设置在基底上的具有大于0.5微米厚度的氧化物超导体膜的氧化物超导体制品,所述制品具有大于或等于约10 5 A / cm 2的传输临界电流密度(Jc) 2>在77K,零场。 氧化物超导体膜的特征在于高Jc和高体积百分比的c轴外延氧化物晶粒,即使厚度高达1微米。 通过提供金属氟氧化物膜制备氧化物超导体制品,所述金属氟氧化物膜包含基本上化学计量比的氧化物超导体的构成金属元素; 以及通过调节从由温度,PH 2 O,PO 2及其组合组成的组中选择的反应参数所选择的转化率将金属氟氧化物转化为氧化物超导体,使得具有传输临界电流密度的氧化物超导体膜 在77K处大于或等于约10 5 A / cm 2,获得零场。