PROBING ATOMIC LEVEL INTERACTIONS IN NI NANORODS AND AFM CANTILEVER USING ATOMIC FORCE MICROSCOPY BASED F–D SPECTROSCOPY

Abstract

Atomic force microscopy based force-displacement spectroscopy is used to quantify magnetic interaction force between sample and magnetic cantilever. AFM based F–D spectroscopy is used widely to understand various surface-surface interaction at small scale. Here we have studied the interaction between a magnetic nanocomposite and AFM cantilevers. Two different AFM cantilever with same stiffness but with and without magnetic coating is used to obtain F–D spectra in AFM. The composite used has magnetic Ni nanophase distributed uniformly in an Alumina matrix. Retrace curves obtained using both the cantilevers on magnetic composite and sapphire substrate are compared. It is found for magnetic sample cantilever comes out of contact after traveling 100 nm distance from the actual point of contact. We have also used MFM imaging at various lift height and found that beyond 100nm lift height magnetic contrast is lost for our composite sample, which further confirms our F–D observation.