Double exchange biased magnetic force microscopy tip and comparison of its imaging performance with commercial tips

Abstract

A double exchange biased magnetic force microscopy tip, which is coated with an antiferromagnet (IrMn)/ferromagnet (CoFe)/antiferromagnet (IrMn) multilayer on one side of a bare tip, has been fabricated and studied. In this design, the CoFe layer can be very thin due to its high moment, which leads to high spatial resolution without sacrificing the signal intensity. The exchange coupling between IrMn and CoFe stabilizes the magnetization of the latter which enables this kind of tip to have a better sensitivity and thermal stability as compared to conventional single ferromagnet layer tips. The performance of the double exchange biased tips has been evaluated through imaging the magnetic patterns recorded on longitudinal magnetic recording media. Micromagnetic modeling has been conducted to understand the underlying mechanism of the tip performance improvement. © 2007 The Japan Society of Applied Physics.