Deposition of a metal-organic heterostructure to form magnetic-nonmagnetic bilayer films

Abstract

Langmuir-Blodgett deposition of a nonmagnetic-magnetic metal-organic bilayer film is reported here. The bilayers consist of a Au nanocluster upper layer over a monolayer of gadolinium stearate (GdSt) deposited on a hydrophilic Si(001) substrate. The morphology of the deposited GdSt layer and upper Au nanocluster layer were systematically analyzed using atomic force microscopy (AFM) and X-ray reflectivity techniques. The morphology of the Au nanoparticle layer changes remarkably depending on the surface pressure of the Langmuir monolayer employed for its transfer on to the gadolinium stearate layer. Three Langmuir phases at different degrees of compression formed the basis for the chosen surface pressure values for the transfer. The bilayer films are an essentially nanostructured network of islands and interconnects that exhibit nonohmic I-V characteristics when measured laterally across the film using a conducting AFM tip.