The Stoner-Wohlfarth model of Ferromagnetism: Static properties

Recent advances in high-density magnetic storage and spin electronics are based on the use of magnetic materials along with conventional microelectronic materials (metals, insulators and semiconductors). The unit information (bit) is stored as a magnetization state in some ferromagnetic ma rial (FM) and controlled with an external field altering the magnetization state. As device size is shrinking steadily toward the nanometer and the need to incr se its bandwidth prevails, racing toward higher frequencies is getting even more cha enging. In magnetic systems, denser storage leads to finer magnetic grains and small size leads to single magnetic domain physics. The Stoner-Wohlfarth model is the simplest model that describes adequately the physics of fine magnetic grains containing single domains and where magnetization state changes by rotation or switching (abrupt reversal). The SW model is reviewed and discussed with its consequences and potential app cations in the physics of magnetism and spin electronics.