Electronic structure, magnetic properties, and microstructural analysis of thiol-functionalized Au nanoparticles: role of chemical and structural parameters in the ferromagnetic behaviour

Abstract

©Springer. We wish to acknowledge the support of the ESRF and BM29 beamline staff. Financial support from the Spanish MEC (NAN2004-09125-C07) and “Junta de Andalucía” (Project P06-FQM-02254, group TEP217) is also acknowledged. E. Guerrero thanks the Spanish MEC for financial support.Gold nanoparticles (NPs) have been stabilized with a variety of thiol-containing molecules in order to change their chemical and physical properties; among the possible capping systems, alkane chains with different lengths, a carboxylic acid and a thiol-containing biomolecule (tiopronin) have been selected as protecting shells for the synthesized NPs; the NPs solubility in water or organic solvents is determined by the protecting molecule. A full microstructural characterization of these NPs is presented in the current research work. It has been shown that NPs capped with alkanethiol chains have a marked ferromagnetic behaviour which might also be dependent on the chain length. The simultaneous presence of Au-Au and Au-S bonds together with a reduced particle diameter, and the formation of an ordered monolayer protective shell, have proved to be key parameters for the ferromagnetic-like behaviour exhibited by thiol-functionalized gold NPs.Spanish MECJunta de AndalucíaDepto. de Física de MaterialesFac. de Ciencias FísicasTRUEpu