Abstract
We have sputtered different thicknesses of Permalloy (Ni79Fe21) on self-assembled monolayers (SAMs) with polar (-COOH) and nonpolar (-CH3) organic functional groups and have observed interesting changes in morphology and magnetic properties. At very low thicknesses (similar to 1.5-3 nm) the morphology and magnetic properties of the deposited Permalloy are similar to those observed for isolated superparamagnetic clusters on both types of SAM surface. Further increase in the deposition (similar to 4 nm and above) of Permalloy results in a ferromagnetic film formation on the polar SAM, and superparamagnetic cluster formation remains apparent on the nonpolar SAM up to a thickness of 8 nm. The polarity of the organic underlayer plays a critical role in this regime. At higher thicknesses (similar to 12 nm and above) Permalloy exhibits usual ferromagnetic behavior on both types of SAM surfaces.