Attachment of FePt–Fe2O3 core–shell nanoparticles on carbon nanotubes and their electrical-transport characteristics



Colloidal FePt–Fe2O3 core–shell nanoparticles (NPs) were chemically synthesized through a two-step process, where FePt NPs were synthesized first and then coated by a Fe2O3 shell. These NPs were attached on the carbon nanotubes (CNTs) by the hydrophobic and van der Waals interaction after the surface functionalization of CNTs in acetone. The NPs-attached CNTs exhibited the threshold switching from the high-resistance state to low-resistance state at a high voltage and vice versa at a low voltage, while the bare CNTs showed ohmic transport. From the conduction mode analysis, it turns out that the threshold switching results from enhanced charge transport by overcoming the energy barrier of Fe2O3 shell at a high voltage.