Ferromagnetic behavior of metallic glasses

Magnetic properties of metallic glasses in the system (Fe‐Co‐Ni) 0.75 (P‐B‐Al)0.25 have been investigated. Samples were made by the roller quenching technique in the form of ribbons 0.002 in. thick and about 0.125 in. wide. Room temperature saturation magnetization, 4πMs, ranged from a high value of 13,500 Gauss for Fe0.75P0.06Al0.03 to essentially zero for Ni0.75P0.16B0.06Al0.03 which exhibits only weak temperature independent paramagnetism. The highest Curie temperatures occurred in mixed Fe‐Co alloys with a high value of 715°K for (Fe0.4Co0.6)0.75 P0.16B0.06Al0.03. The sign of the magnetostriction was found to change from positive for Fe rich alloys to negative for Co rich alloys so that low or zero magnetostriction composition can be made near the Co rich side of the pseudo‐ternary phase field. For example (Fe0.04Co0.96)0.75P0.16B0.06 Al0.03 has nearly zero magnetostriction. This alloy responds to heat treatment in a magnetic field, developing properties which compare favorably with commercial superma...