1 Magnetoresistance in Thin Permalloy Film (10nm-thick and 30-200nm-wide) Nanocontacts Fabricated by e-Beam Lithography.

In this paper we show spin dependent transport experiments in nanoconstrictions ranging from 30 to 200nm. These nanoconstrictions were fabricated combining electron beam lithography and thin film deposition techniques. Two types of geometries have been fabricated and investigated. We compare the experimental results with the theoretical estimation of the electrical resistance. Finally we show that the magnetoresistance for the different geometries does not scale with the resistance of the structure and obtain drops in voltage of 20mV at 20Oe. 2 Nowadays technologies for communications, automotive, medical and other areas of interest are demanding more and more nanometer size integrated structures. One of the fields that lately have taken more attention is spintronics.. The discovery of giant magnetoresistance using magnetic and non-magnetic multilayers(1,2) represented a change. These systems work with a good stability because the materials are all metallic and conduction is good so that reasonable currents (mA) can be kept stable. Also gian