Electrical transport study of magnetomechanical nanocontact in ultrahigh vacuum using carbon nanowalls

Abstract

We present the results of an experimental study on a magnetomechanical nanocontact in ultrahigh vacuum, which is formed between a Ni nanoprobe and carbon nanowalls. The latter are thin graphite sheets grown almost vertically on a SiO2/Si substrate which greatly facilitates the formation of nanocontacts with adjustable contact size. Very large magnetoresistance with well-defined hysteresis and reproducibility has been observed at room temperature, which is interpreted as being caused by the magnetomechanical effect. Instead of functioning merely as an on/off switch, the linear response to an external field within a finite range makes this kind of nanocontact potentially also useful for sensing applications. © 2010 American Institute of Physics.