Ultra fine, ultra soft metallic fibres

Fine metallic and ceramic fibres with diameters ranging from 5 to 25 microns and lengths up to several meters have been produced by a simple single step fabrication process based on the melt extraction technique. The technology developed permits the production of fine fibres of amorphous or crystalline material from liquids with extremely low viscosity and high surface tension, parameters normally inhibiting fibre production by drawing and similar technologies. We believe that magnetic and mechanical properties of the fibres are linked to complex magnetic and crystallographic structures reflecting the formation of a free surface and "frozen" stress introduced during the radial cooling from the surface to the line of contact. The quenched-in stress strongly affects the crystallographic and magnetic domain structure, and the easy axis of magnetization is usually perpendicular to the fibre length. Examples of practical applications are presented, such as: anti-theft devices, proximity, stress, identification and magnetoresistive sensors.<>