Switching Field Distributions in Submicron Magnetic Wires Connecting to Square Pads.

The distributions of the switching field (HSW) for single magnetic wires (150 nm width) were investigated as a function of temperature between 5 and 300 K. One end of each wire was connected to a square pad (large area), and magnetization reversal phenomena were very sensitively detected by using the giant magnetoresistance effect. While the distribution width of the HSW for the Co layer in NiFe/Cu/Co drastically broadened below 100 K, that of the HSW for the NiFe layer in NiFe/Cu/NiFe had three narrow peaks at each temperaure down to 5 K. The origin of these three peaks can be attributed to the existence of three different kind of magnetic domain structures in the pad area, which was suggested by MFM observation.