Abstract
FePt is an important material in magnetic application because of its large uniaxial magneto crystalline anisotropy (Ku >7x10[6] J/m[3]) and good chemical stability. To use on the real hard disk product, a long-term and ordered arrangement of nanoparticles is a requisite goal. We use self-assembled amino-functional substrates to adsorb FePt nanoparticles, and try to increase the coverage of the nanoparticles. We prepare three different chain length amino-functional substrates, cystamine dihydrochloried, dodecylamine, and octadecylamine. We Study the adsorption of FePt nanoparticles on the amino-functional substrates with quartz crystal microbalance and Rutherford backscattering spectrometry. And we use atomic force microscope to measure the roughness of the amino-functional substrates. We find that cystamine dihydrochloride substrate has the lowest adsorption of FePt nanoparticles, it may due to the weak intermolecular interactions between short alkyl-chains, so it is difficult to form two dimensional monolayer. Another reason is that cystamine dihydrochloride dose not form monolayer, therefore we find it has the largest roughness. Dodecylamine has the maximum adsorption of FePt nanoparticles, and the coverage is about 38% to 58%. Compared with the coverage 68% of APTS, it still has some effort to do. To increase the coverage of FePt nanopartiles, we can increase the reaction temperature when the self-assembled monolayer grew up.