Synthetic metamagnetism -- magnetic switching of perpendicular antiferromagnetic superlattices

Recently synthesized antiferromagnetically coupled multilayers [CoPt]/Ru with strong perpendicular magnetic anisotropy (Nature Mater. 2 (2003) 112) represent a new class of magnetic materials with unique magnetic properties. It is shown that they are characterized by a cascade of metamagnetic phase transitions with unusually broad regions of metastable phase-coexistence and are accompanied by specific multidomain structures. By tuning parameters like interlayer exchange, anisotropy and geometry, a well-defined sequence of magnetic switching transitions of individual layers can be realized in prescribed magnetic fields. Artificial layered systems of this kind with a controlled variation of distinct magnetic states in vertical direction through the stack may lead to a new paradigm for, and novel types of, high-density media in magnetic recording and spin electronic technologies