ELECTRODEPOSITION OF NANOSCALE MAGNETIC-STRUCTURES

Magnetic Co clusters have been electrodeposited from an aqueous electr olyte onto Au surfaces in an electrochemical scanning tunneling micros cope (STM). In a two-step electrochemical process, Co is first deposit ed onto a Au STM tip, then completely dissolved, and locally deposited onto the substrate underneath the STM tip due to local Co2+ oversatur ation, which results in a laterally varying increase of the Co/Co2+ Ne rnst potential at the substrate surface. Mechanical tip-sample contact s or creation of substrate defects can be excluded. The structure size is of the order of the STM tip apex diameter, and is in detail determ ined by the substrate potential. (C) 1998 American Institute of Physic s. [S0003-6951(98)00348-9].