摘要:
A composite material is disclosed which includes a substrate, an oriented film provided on a surface of the substrate and formed of a crystal of a Y123 metal oxide of the formula LnBa.sub.2 Cu.sub.3 O.sub.y wherein Ln stands for Y or an element belonging to the lanthanoid and y is a number of 6-7, and a layer of a Y123 metal oxide of the formula LnBa.sub.2 Cu.sub.3 O.sub.y wherein Ln stands for Y or an element belonging to the lanthanoid and y is a number of 6-7 formed on the oriented film.
摘要:
A composite material is disclosed which includes a substrate, an oriented film provided on a surface of the substrate and formed of a crystal of a Y123 metal oxide of the formula LnBa.sub.2 Cu.sub.3 O.sub.y wherein Ln stands for Y or an element belonging to the lanthanoid and y is a number of 6-7, and a layer of a Y123 metal oxide of the formula LnBa.sub.2 Cu.sub.3 O.sub.y wherein Ln stands for Y or an element belonging to the lanthanoid and y is a number of 6-7 formed on the oriented film.
摘要:
The present invention is directed to a method for growing a superconductive film on a superconductive substrate in order to produce a bulk single crystal. According to a preferred embodiment, an oxide superconductive film of a material which is the same or similar to the substrate material is epitaxially grown at a temperature between 450.degree. C. and 800.degree. C. so that the film and substrate have the same lattice orientations. According to the present invention, problems associated with conventional films having non-superconductor substrates (e.g., MgO and SrTiO.sub.3) are avoided.
摘要:
A method of pulling a crystal of a metal oxide is disclosed, in which the growth of the crystal is performed in a liquid phase having a composition which is different from the metal oxide and which contains components constituting the metal oxide. The liquid phase is in contact with a solid phase located at a position separated from the position at which the crystal of the metal oxide grows. The solid phase has a composition different from that of the metal oxide and supplies components constituting the metal oxide to the liquid phase.
摘要:
The generation of a reaction product is suppressed between a metallic substrate and plasma in depositing a ceramic intermediate layer on the metallic substrate in a process for depositing an oxide film on the metallic substrate by thermal plasma flash evaporation method. Thus, there is no reaction phase in the ceramic intermediate layer and the metallic substrate, and an intermediated buffer layer of only oxide ceramic is deposited on a flat surface of the metallic substrate. The intermediate ceramic layer is deposited in inert atmosphere of a low oxygen concentration at a temperature of less than 600.degree. C. for the metallic substrate. Then, a superconducting thin film is deposited on the ceramic intermediate layer.
摘要:
A composite material comprising a bulky substrate of a Y-series 123 metal oxide crystal, and at least one layer provided on a surface of the substrate and formed of a crystal of a Y-series 123 metal oxide. The substrate may be produced by immersing a seed material in a liquid phase which comprises components constituting the metal oxide. The liquid phase contains a solid phase located at a position different from the position at which the seed material contacts the liquid phase. The solid phase provides the liquid phase with solutes which constitute the Y-series 123 metal oxide so that the solutes are transported to the position at which the seed material and the liquid phase contact, thereby permitting the Y-series 123 metal oxide to grow on the seed material as primary crystals and to obtain the bulky substrate. The layer of a Y-series 123 metal oxide may be formed on the substrate by a sputtering method, a vacuum deposition method, a laser abrasion method, a CVD method or a liquid phase epitaxy method.
摘要:
A method of preparing a crystal of a Y-series 123 metal oxide is disclosed, in which a substrate is immersed in a liquid phase which comprises components constituting the metal oxide. The liquid phase contains a solid phase located at a position different from the position at which the substrate contacts the liquid phase. The solid phase provides the liquid phase with solutes which constitute the Y-series 123 metal oxide so that the solutes are transported to the position at which the substrate and the liquid phase contact, thereby permitting the Y-series 123 metal oxide to grow on the substrate as primary crystals.
摘要:
A superconductor comprising a compound of the formula (II):R.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.7-y1 (II)wherein not less than 40% of a crystal of the superconductor shows phase separation, and at (temperature, magnetic field) of (77�K!, O�T!) and (77�K!, 4�T!), a critical current density is not less than 10,000 A/cm.sup.2, which is obtained by heating a precursor which is a solid solution of the formula (I):R.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.7-y (I)wherein not more than 10% of a crystal of the solid solution shows phase separation, so that phase separation is formed in the crystals at a phase separation temperature, and introducing oxygen; and a superconductor comprising a compound of the formula (II):R.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.7-y1 (II)wherein not more than 10% of a crystal of the superconductor shows phase separation, and in a magnetic field of not less than 1�T! at a constant temperature of 77�K!, a critical current density is less than 10,000 A/cm.sup.2, which is obtained by introducing oxygen into the precursor (I) at a temperature less than the lower limit of the phase separation temperature. According to the method of the present invention, a superconductor having a high Jc or having different properties with respect to Jc, which is unobtainable by the conventional production method, can be obtained using the conventional materials.
摘要:
The present invention is aimed to provide a means for manufacturing a RE123 system oxide superconductor showing good superconductivity characteristics under atmospheric ambiance. In a method of manufacturing a RE123 system oxide superconductor by melting, cooling and solidifying material including rare-earth elements and a Ba--Cu--O solvent for crystallization such as by the crystal pulling method, examining beforehand the relationship between the melted material composition and the equilibrium liquid-phase composition and the crystal composition of the RE123 system oxide superconductor formed therefrom in atmospheric ambiance, and based on the result of said examination, adjusting the average composition of the material or the composition of the solvent (for example, setting the average composition of the material to an area where the superconductivity phase and the liquid phase coexist in equilibrium, and at the same time adjust the "Ba/Cu" ratio of the melted material to 3/5-1/1, or adjust the "Ba/Cu" ratio of the solvent inside the crystal pulling crucible to 3/5-1/1), in order to control the amount of mutual substitution between RE and Ba (control the value of x in RE123 system superconductor RE.sub.1+x Ba.sub.2-x Cu.sub.3 O.sub.7-d to 0-0.05 and the like) for crystallization.
摘要:
In order to stably retain an oxide-based melt consisting essentially of yttrium or a lanthanoid element, barium, copper and oxygen at a prescribed temperature with no impurity contamination thereby preparing a large oxide crystal of high quality from the melt, an oxide melt consisting essentially of yttrium or a lanthanoid element, barium, copper and oxygen is stored in a first crucible, which in turn is held in a second crucible. The first crucible is made of a material which is an oxide of at least one element forming the melt having a melting point higher by at least 10.degree. C. than a melt retention temperature and causing no structural phase transition up to a temperature higher by 10.degree. C. than the aforementioned prescribed temperature, with solubility of not more than 5 atomic percent with respect to the melt in a temperature range from the room temperature to a temperature higher by 10.degree. C. than the melt retention temperature. The second crucible is made of a material substantially causing neither melting nor chemical reaction with respect to the oxide-based melt, which can retain the melt more stably than the first material. Even if the melt overflows the first crucible, this overflow is suppressed by the second crucible. It is possible to prepare a crystal of an oxide superconductor such as YBa.sub.2 Cu.sub.3 O.sub.7-x (0.ltoreq.X.ltoreq.1) by the pulling method from the melt which is stored in the first crucible.