Magnetization Switching of Co Nano Magnets by Current Pulses

Two kinds of Co thin film nanomagnets with multi-domain and single-domain in the structure of IrMn (8 nm)/Co (11 nm)/Cu (2 nm)/Co (2 nm)/Cu (2 nm)/Au (5 nm)/Cu (100 nm) are prepared and the resistance change by the magnetic field and electric current have been studied. From current induced magnetization switching (CIMS) and pulse effect, it is estimated that the switching time in the multi-domain CIMS device is smaller than 2 nsec and would suggest that the domain structure is a crucial factor in determining the switching time, not the switching current.