Resistance changes similar to ballistic magnetoresistance in electrodeposited nanocontacts

We have studied the behavior of electrodeposited Ni and Fe nanocontacts in magnetic fields and the changes in resistivity (DeltaR) that occur. Metallic particles suspended in plating solution, created and collected from the electroplating bath of a nanocontact that later exhibited high values of DeltaR/R, have been transferred to a second set of electrodes, in which similar high values of DeltaR/R were measured without any plating process being performed. We attribute this effect to a mechanical reorientation of magnetic nanoparticles at the junction between the electrodes as the field is close to zero, and relate this work to present work with ballistic magnetoresistance in nanocontacts. We also show that Fe whiskers brought in close contact can produce this effect as well. (C) 2004 American Institute of Physics.