Fabrication and magnetic study of Co/Pt multilayer nanowires and Co-Pt alloy nanowires electrodeposited into porous Si substrates

In this work, we grow composite structures consisting of magnetic and non-magnetic metal or alloy nanowires electrodeposited into the ion etched tracks previously created inside Si substrates. The holes are then filled by Co-Pt alloys and Co/Pt multilayers using electrodeposition technique making a large number of parallel nanowires. This process takes place in a single electrolyte containing Co+2 and Pt+4 ions by applying a proper deposition potential using a computer control potentiostat. The magnetic properties of the sample were studied using vibrating sample magnetometer. Magnetoresistive behaviour of the nanowire samples was then studied by subjecting the samples to an external magnetic field. The results show that the Co/Pt multilayered nanowires exhibit a large magnetoresistance, while the Co-Pt alloys only show anisotropic magnetoresistance. This result could be of a great interest for the sensor fabrication community as they will provide a view on a very important direction of the development of the wide spread sensor industry, and more importantly for understanding the physical phenomena underlying the magnetic/non-magnetic nanostructures.