Fabrication and quantum conductance of electroplated Ni nanocontacts

Nanometer scale Ni contacts are electrodeposited between microfabricated Au(100 nm) leads separated by 100 nm obtained by the combination of optical lithography and focused ion beam etching of Si(0.2 mm)/SiO2(100 nm)/Ti(10 nm)/Au(100 nm) wafers. Quantum changes (2e2/h)(2e2/h) in conductance are observed in-situ during electrodeposition and dissolution processes. The explanation of these observation lies in the creation of nano-meter scale wires during both opening and closure of the contact as evidenced by field emission scanning electron microscopy.