Interfacial oxidation for spin transport in Fe3O4/sulfonic acid molecule nanoparticles

Abstract We fabricated the Fe3O4/alkyl-sulfonic acid molecules hybrid nanoparticles by self-assembly monolayers (SAMs) in air and nitrogen ambience to investigate the impact of the oxidation on the spin transport. X-ray photoelectron spectra (XPS) and Fourier transform infrared (FTIR) spectroscopy measurements infer that the chemical bonding between Fe3O4 and alkyl-sulfonic acid remains unchanged as interfacial oxygen content reduced. The resistivity of nitrogen ambience synthesized sample is 1/3 of that in air indicates more tunneling channels are active in less oxygen content samples. The stable and robust room temperature tunnel magnetoresistances up to ∼10% is observed for both ambience fabrication samples, demonstrating that the magnetoresistance in Fe3O4/sulfonic acid nanoparticles is not sensitive to the oxygen. These provide Fe3O4/molecule interface as a promising candidate for spintronic applications.