Dependence of thermomagnetic mark size on applied STM voltage in Co-Pt multilayers

A method of heat-assisted magnetic recording potentially suitable for proposed probe-based storage systems is characterized. In this paper, a scanning tunneling microscope (STM) is used as the heating source. Pulse voltages of 1-8 V with duration of 500 ns were applied to a Co-Pt multilayered film, while the STM tip was held at a position set by a steady-state bias voltage of 20 mV and a tunneling current of 2 nA. Our results show that thermally recorded magnetic marks are formed with a nearly uniform mark size of 220 nm when the pulse voltages are between 2 and 8 V. This is very close to the theoretical minimum domain size in these films. For pulse voltages below the threshold of 2 V, no marks are formed.