Off-axis electron holography of nanomagnet arrays fabricated by interferometric lithography
Arrays of sub-micron sized magnetic elements are of interest for future high-density magnetic recording applications. Here, we use off-axis electron holography in the TEM to characterise square arrays of submicron-sized Co and Ni nanomagnets that have been patterned onto Si using interferometric lithography. Electron holography involves the use of a field emission gun TEM to provide a coherent source of electrons and an electrostatic biprism to overlap an electron wave that has passed through the sample with one that has passed only through vacuum. Information about magnetic fields in the sample is recorded in the local position (the phase) of the holographic interference fringes that form in the overlap region.