(Fe,Mn)₃O₄ nanochannels fabricated by AFM local-oxidation nanolithography using Mo/poly(methyl methacrylate) nanomasks

A novel method to fabricate (Fe,Mn)₃O₄ (FMO) thin-film epitaxial nanostructures employing atomic force microscopy (AFM)-fabricated Mo/poly(methyl methacrylate) (PMMA) nanomasks and wet chemical etching, is discussed. Nanomasks were realized by combining local anodic oxidation (LAO) of Mo and dry etching of PMMA. Nanostructures with dimensions of 100 nm can be easily fabricated with this technique, and the nanomask can be removed by ultrasonication in acetone. FMO nanochannels show transport properties similar to those of films, which exhibit room-temperature ferromagnetism and present the possibility of fabricating spin-polarized nanometer-scale circuits for spintronics. Nanogap electrodes can be fabricated on prepared nanochannels by Mo/PMMA masks using lift-off procedures, or the magnitude nanochannels themselves can be realized by wet etching through Mo/PMMA masks realized on metallic nanogap-electrode templates.