Remanent magnetization states and interactions in square arrays of 100-nm cobalt dots measured using transmission electron microscopy

Large area square arrays of circular cobalt dots, nominally 100 nm in diameter and 20 nm in thickness are patterned using interference lithography and magnetic remanent states are measured using off-axis electron holography in the transmission electron microscope. The results reveal that the dots are mostly single domain, although vortex states and multidomain configurations are occasionally observed.