Magnetization Discontinuities in Cobalt-Rare-Earth Particles

Abstract

Hysteresis loops of single particles of Co₅Sm have previously shown that magnetization discontinuities (jumps) occur at fields H_n that are quite discrete and whose values depend on the previous magnetizing field H_m. Some effects of chemical polishing and air aging on the values of H_n and their H_m dependence in Co₅Sm particles are described. Jumps have now been observed in Co₅Y. A particle of Co₅Y showed a rectangular hysteresis loop with H_n=3800 Oe for H_m of only 4100 Oe, the loop remaining unchanged for H_m up to 30 kOe, and a maximum energy product of 27.6×10⁶ G Oe.