摘要:
A process for the manufacturing of 100% dense TMC bulk material by hot isostatic pressing (HIP) for manufacturing of ternary molybdenum chalcogenide (TMC) single or multifilamentary superconducting wires, in particular that of SnMo6S8 (SMS) and PbMo6S8 (PMS). Such wires allows generation of magnetic fields in excess of 24 Tesla, the limit of the presently used Nb3Sn wires. In addition, TMC superconducting wires are complementary to Nb3Sn because they have about four times higher mechanical strength, i.e., yield strength Rp02. The deformation process by hot extrusion and the hot wire drawing allow plastic/superplastic deformation of the TMC superconductor with perfect grain boundaries, increase the critical current density. Further, the use of high purity molybdenum, with a residual resistivity ratio of at least 100, is considered as an additional inventive step because molybdenum serves not only as a diffusion barrier but simultaneously as electrical stabilizer.
摘要:
Techniques for forming metal contacts to LMDC-based devices are provided. In one aspect, a method of forming a metal contact to a LMDC semiconductor material includes the steps of: depositing a contact metal onto the LMDC semiconductor material; and annealing the LMDC semiconductor material and the contact metal under conditions sufficient to react the contact metal with the LMDC semiconductor material and thereby form a buffer layer as an interface between the contact metal and the LMDC semiconductor material that compositionally is a transition from the LMDC semiconductor material to the contact metal and connects the LMDC semiconductor material and the contact metal by covalent bonds. The LMDC semiconductor material can be a material having a formula MX2, wherein M is a metal, and X is a chalcogen. A LMDC-based device and techniques for forming the device are also provided.
摘要:
A process for the production of at least a one kilogram block of Chevrel-phase Pb.sub.x Mo.sub.y S.sub.z, wherein x=0.9 to 1.2, y=6.0 to 6.4, and z=7 to 8, includes mixing thoroughly stoichiometric quantities of starting materials in powdered form. The starting materials are selected from elemental Pb, Mo and S, sulfides of elemental Pb and Mo, and mixtures thereof. The starting mixture is introduced into a metallic container and evacuated to a pressure to 10.sup.4 Pa or less. The evacuated container is subjected to hot isostatic pressing at a constant pressure selected from a pressure ranging from 100 to 300 MPa, at a heating rate ranging from 10.degree. to 100.degree. C./hr., at a final pressing temperature ranging from 800.degree. to 1200.degree. C., and for a pressing period ranging from 10 to 100 hours, whereby the starting materials react to form the block of Chevrel-phase Pb.sub.x Mo.sub.y S.sub.z. The block is cooled at a cooling rate ranging from 50.degree. to 500.degree. C./hr. while maintaining the constant pressure. The process may include the further steps of filling the metallic container after evacuation with an inert gas; re-evacuating the metallic container to remove the inert gas; and heating the metallic container after re-evacuation at a temperature ranging up to but less than 300.degree., prior to subjecting the metallic container to hot isostatic pressing.
摘要:
A hybrid superconductive fiber or strand comprises at least two layers surrounding a core wherein the fiber or strand comprises two superconductive materials. One of the superconductive materials is a Chevrel phase, optionally doped, which constitutes one of the layers or the core. The other superconductive material, other than the Chevrel phase, constitutes another layer, optionally lacunar, or the core.
摘要:
The present invention is designated to solve such problems whereby a process for producing a PbMo.sub.6 S.sub.8 type compound superconductor excellent in stoichiometric composition and electric characteristics can be provided.In addition to the above, another purpose of the present invention is to provide a process for producing a PbMo.sub.6 S.sub.8 type compound superconductor with stable electrical characteristics.
摘要:
In some embodiments of the invention, superconducting structures are described. In certain embodiments the superconducting structures described are thin films of iron-based superconductors on textured substrates; in some aspects a method for producing thin films of iron-based superconductors on textured substrates is disclosed. In some embodiments applications of thin films of iron-based superconductors on textured substrates are described. Also contemplated is the formation of a film of iron-based superconductor having a thickness and an in-plane lattice constant formed on a textured substrate having a thickness and an in-plane lattice constant similar to the in-plane lattice constant of the iron-based superconductor.
摘要:
A method for producing a superconductive wire, whereby an elongated intermediate element is formed out of an initial element in a deformation step and whereby the superconductive filaments are formed by a final reaction heat treatment, is characterized in that prior to the final reaction heat treatment the filaments in the intermediate element are densified in one or more high pressure densification steps following up the deformation step, said densification steps comprising a simultaneous action of at least four hard surfaces perpendicular to the axis of the elongated intermediate element, building up high pressure P≧100 MPa on a part of the intermediate element having an axial length L. This leads to a substantial increase of the critical current density Jc, whereby the anisotropy factor F is be almost not affected thus enabling production of almost isotropic wires or tapes.
摘要:
Process for increasing the density and improving the homogeneity of Chevrel phase powders and Chevrel phase wire obtained using said process. Chevrel phase powers are compounds of lead, mobydenum, and sulfur. Metallic additives in the range of 0.5% to 20% by weight are introduced in the Chevrel phase powders by a physical or chemical process. The melting temperature of the metallic additives is lower than the synthesis temperature of the Chevrel phase powders so as to increase the homogeneity. The wires obtained using this process are capable of generating high magnetic fields.
摘要:
This invention relates to the manufacture of Chevrel phase compounds by sintering a mixture of metal sulfides, metallic molybdenum and molybdenum sulfides under reduced pressure or in a stream of an inert gas containing a reductive gas, and by sintering a mixture of metal sulfides and molybdenum sulfides in a stream of an inert gas containing a reductive gas. This process does not need any complicated procedure as in the prior art and enables one to use a reaction container a desired number of times and to prepare Chevrel phase compounds inexpensively in large amounts.
摘要:
A powder having a predetermined composition is filled in a tube. The tube is drawn to obtain a wire and the wire is rolled to obtain a tape-like starting body. Then, a laser beam is irradiated on the part of the tape to heat and melt the part of the tape. The starting body is rapidly heated and then cooled, thereby the part of the starting body is melted and solidified to form a compound superconductor layer.