Microcantilever Torque Magnetometery Study of Patterned Magnetic Films

Microcantilever torque magnetometry (MTM) is a sensitive tool to measure small magnetization changes in the sample. In this paper, we investigated a process for preparing patterned magnetic films on cantilevers and studied the magnetic interactions of a single pair of micrometer-sized Ni 80 Fe 20 bars (7 mum times 3.5 mum times 30 nm) separated by 50 nm using MTM. The bars were prepared with focused ion-beam milling. The magnetic hysteresis loops show that the switching field of a single bar is larger than the reversing field of only one of the paired bars and less than that of both paired bars. This clearly indicates that the magnetostatic interaction exists between the bars