ULTRA-FINE, ULTRA-SOFT METALLIC FIBERS

Fine metallic and ceramic fibres with diameters ranging from 5 to 25 m icrons and lengths up to several meters have been produced by a simple single step fabrication process based on the melt extraction techniqu e [1]. The technology developed permits the production of fine fibres of amorphous or crystalline material from liquids with extremely low v iscosity and high surface tension, parameters normally inhibiting fibr e production by drawing and similar technologies. We believe that magn etic and mechanical properties of the fibres are linked to complex mag netic and crystallographic structures reflecting the formation of a fr ee surface and ''frozen'' stress introduced during the radial cooling from the surface to the line of contact. The quenched-in stress strong ly affects the crystallographic and magnetic domain structure, and the easy axis of magnetization is usually perpendicular to the fibre leng th. Examples of practical applications are presented, such as: antithe ft devices, proximity, stress, identification and magnetoresistive sen sors.