Magnetic nanostructure fabrication by focused ion beam milling

Summary form only given. Magnetic nanostructures with sub-100 nm features are usually fabricated by e-beam lithography but the process involves several steps and can be time inefficient in the production of small numbers of development samples. We report here the use of focused ion beam (FIB) milling to directly pattern ferromagnetic thin films as a rapid method of fabricating nanostructures. 5 nm thick, thermally evaporated Permalloy (Ni/sub 80/Fe/sub 20/) films were patterned with 30 keV Ga/sup +/ ions. The FIB spot diameter was 10 nm and, after milling depth calibration, an ion dose density of 11 cm/sup -2/ was used to ensure the complete removal of Permalloy at milling sites.