LOCALIZED HEATING OF NICKEL NITRIDE ALUMINUM NITRIDE NANOCOMPOSITE FILMS FOR DATA-STORAGE

Nickel-aluminum nitride films were prepared by reactive sputtering of a nickel aluminide plate in a nitrogen plasma, The initial product is a nanocomposite containing the nickel as the nitride, Ni3N, in aluminu m nitride. Heating in vacuum to 500 degrees C causes selective decompo sition of the thermally labile nickel nitride leaving the aluminum nit ride unaffected, The nickel nanocomposite is of interest for potential applications as recording media, as are other finely divided dispersi ons of ferromagnetic metals in insulating matrices. The nickel-aluminu m nitride nanocomposite shows a moderate coercive field of 35 Oe at 30 0 K and, in common with ultrafine particles of ferromagnetic materials , shows superparamagnetic behaviour. The Ni3N/AlN nanocomposite was su bjected to localized heating with the focused beam of an argon-ion las er; this created features several microns in width that could be image d with a magnetic force microscope, thus confirming its potential as a high density data storage medium. (C) 1995 American Institute of Phys ics.