Abstract: A method of making a solid magnetic material from Sm.sub.2 Fe.sub.17 N.sub.3-x type intermetallic nitride powder, where 0.ltoreq.x.ltoreq.1, comprises the following steps:a--the powder is mixed intimately with glass powder having a conversion temperature Tg between 260.degree. C. and 310.degree. C. and a softening temperature Tf less than 400.degree. C., the proportion of glass powder being between 10% and 30% of the total volume;b--the mixture is compressed to obtain a solid;c--the solid obtained is subjected in a neutral gas atmosphere to a heat cycle during which a temperature not less than Tf+5.degree. C. and not more than 420.degree. C. is maintained for at least one hour.

Abstract: A superconducting strand comprises a central superconducting filament (1), a covering (2) of oxide for ensuring sufficient oxygen pressure around the filament (1), a layer of cladding (3) made of aluminum, an alloy of copper and aluminum, or of stainless steel, a layer of cladding (4) made of niobium, of tantalum, or of vanadium, and an outer covering of copper (5).

Abstract: The method is intended to provide cables (10) having an optical fiber (1) and suitable for mechanically severe environments, while remaining small in section. Heretofore, the mechanical strength of optical fiber cables has been obtained by plastic structures of considerable cross-sectional area and reinforced by metal strands or by glass fibers. In the method of the present invention, the reinforcing is obtained by metal composites (3) having very high mechanical strength and very small diameter, said composites extending parallel to the fiber (1).

Abstract: Multifilament superconductor strands of less than 1 mm diameter able to carry alternating current are stranded to a pitch of between 7 and 3 diameters, at a temperature above 200.degree. C. and a speed between 30 and 5,000 rpm.

Abstract: The present invention concerns superconductor lengths constituted by superconducting filaments based on a ternary chalcogenide of molybdenum (PbMo.sub.6 S.sub.8) assembled within a stabilizing matrix based on copper. The invention provides a method of fabricating superconducting filaments consisting of mixing a powder of a ternary chalcogenide of molybdenum with a metal powder of smaller granulometry and chosen from the components of the chalcogenide in question, or from the group of metals consisting of aluminum, silver, gallium, rhenium, and titanium, in sheathing the mixture of powders obtained by means of a metal wall constituted from one of a group of metals formed by molybdenum, niobium, tantalum, titanium and vanadium, and in subjecting the superconducting lengths obtained after drawing and cold working using conventional wire drawing techniques to a final heat treatment consisting of heating to a temperature of about 800.degree. C. for at least twenty hours.

Abstract: A superconductor manufacturing process provides electrical insulation and enhanced transverse electrical resistivity of multifilament superconductor strands based on Nb.sub.3 Sn. The process includes forming, during the early manufacturing steps in which the product is relatively short and of large cross section, resistive barriers around bundles of filaments in an oxide powder doped with conductive materials. In subsequent steps, an electrically insulative powder is used to insulate between a copper tube surrounding the bundles of filaments and an outer resistive ring or to insulate around multifilament strands.