Observation of recoil magnetization curves outside the major loop in Co, Fe, and Ni films
J. Geshev, Wagner Jesus da Silva Garcia, V. Z. C. Paes, L. F. S. Azeredo, Lucio Strazzabosco Dorneles, A. M. H. de Andrade
Abstract
We report a peculiar magnetization reversal observed in magnetron-sputtered Co, Fe, and Ni films. We found that some recoil (minor) magnetization curves lie entirely and way outside the major loop, a phenomenon referred to here as a recoil-curve overshoot. The greatly enhanced recoil curve's remanence and coercivity result in an up to 2.5-fold increase of loop's area. The model of pairs of exchange-coupled grains with misaligned anisotropy axes reproduces, in a very good agreement with the experiment, all key features of the recoil-curve overshoot as well as the kink that some major loops present before saturation. The disclosed features of the ferromagnetic hysteresis provide further insights into this important classical phenomenon.