2013 年 37 巻 3-1 号 p. 56-61
Magnetic force microscope (MFM) tips are prepared by coating Si tips of 4 nm radius with 80-nm-thick FePd-alloy films at room temperature followed by annealing at temperatures ranging between 200 and 600 °C. The effects of annealing temperature on the spatial resolution and the switching field of MFM tip are investigated. It has been shown that an MFM tip with resolution bellow 10 nm and switching field of 1.5 kOe can be prepared by FePd-alloy film coating. The resolution is nearly constant at 8.8 ± 0.3 nm for tips annealed at temperatures lower 550 °C, while it deteriorates to 9.4 ± 0.3 nm by 600 °C annealing. The variation of spatial resolution is related with an increase in surface roughness of film-coated tip caused upon annealing. The switching field is shown to depend on the degree of L10 ordering in FePd film. It increases from 0.25 to 1.5 kOe by increasing the annealing temperature from 200 to 600 °C, where the order degree in FePd film increases from 0 to 0.84.