  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.
