This work constitutes a detailed study of electrical and magnetic properties in nanometric materials with a range of scales: atomic-sized nanoconstrictions, micro- and nanowires and thin films. Firstly, a novel method of fabricating atomic-sized constrictions in metals is presented; it relies on measuring the conduction of the device while a focused-ion-beam etching process is in progress.

This work constitutes a detailed study of electrical and magnetic properties in nanometric materials with a range of scales: atomic-sized nanoconstrictions, micro- and nanowires and thin films. Firstly, a novel method of fabricating atomic-sized constrictions in metals is presented; it relies on measuring the conduction of the device while a focused-ion-beam etching process is in progress.