Electrodeposited PdNi as possible ferromagnetic contacts for Carbon nanotubes.

A process for electrodepositing PdNi alloys and subsequent characterisation studies are reported. PdNi alloys are deposited on 0.019-0.021 Ω.cm and 1-2 Ω.cm n-type Silicon from a bath of Pd-ethylenediamine dichloride and Ni sulphate. The deposited films form excellent Schottky barriers on 1-2 Ω.cm Si with leakage currents of the order of µA/cm2 and forward current higher than the reverse current by about six orders of magnitude at 1V. Ni atomic fractions in the deposited films are studied for different bath concentrations and the deposition potential was found to play an important role in deciding the composition of the deposited film. For high Ni concentration solutions, it is possible to deposit films with a wide range of Ni content by varying the deposition potential, while this method cannot be used with low Ni concentration solutions. Films with Ni concentrations above 30% were observed to be ferromagnetic at room temperature and ferromagnetic properties strengthened with Ni content. A structure for a carbon nanotube device is proposed and electrical characterisations of the device using PdNi alloy contacts are presented. The Schottky barrier characteristics and ferromagnetic character make PdNi alloys a good material for ferromagnetic contacts to CNTs on a Si substrate