122 research outputs found
Critical Hysteresis from Random Anisotropy
Critical hysteresis in ferromagnets is investigated through a -component
spin model with random anisotropies, more prevalent experimentally than the
random fields used in most theoretical studies. Metastability, and the
tensorial nature of anisotropy, dictate its physics. Generically, random field
Ising criticality occurs, but other universality classes exist. In particular,
proximity to criticality may explain the discrepancy between
experiment and earlier theories. The uniaxial anisotropy constant, which can be
controlled in magnetostrictive materials by an applied stress, emerges as a
natural tuning parameter.Comment: four pages, revtex4; minor corrections in the text and typos
corrected (published version
- …