A model of heat transfer in STM-based magnetic recording on CoNi/Pt multilayers

A method of heat-assisted magnetic recording (HAMR) potentially suitable for probe-based storage systems is characterized. In this work, field emission current from a scanning tunneling microscope (STM) tip is used as the heating source. Pulse voltages of 3-7 V with a duration of 500 ns were applied to a CoNi/Pt multilayered film which is fabricated on a bare silicon and oxidized silicon, respectively. For both substrates, write threshold voltage of 4 V was observed. Above threshold, mark size was 170 and 260 nm for the films on bare silicon and oxidized silicon, respectively. A model of 2-D heat transfer in a multilayered film structure was applied and the mark size difference was explained by the thermal conductivity of the substrate.