Tuning morphology and magnetic properties of sputtered permalloy by organic underlayers

We report the effect of polarity of self-assembled monolayers on magnetic properties and morphology of a deposited magnetic material. Sputtering of permalloy (Ni79 Fe21) on a patterned structure of self-assembled monolayers (SAMs), with -COOH and -C H3 terminal groups, results in the formation of a film on -COOH regions and clusters on -C H3 regions. Further investi-gations reveal that the cluster formation gives rise to superparamagnetism, while the film shows usual ferromagnetic behavior. The observed contrast in morphology and magnetism of permalloy is attributed to different growth mechanisms arising from the difference in reactive nature of the terminal functional groups of the SAMs.