Conducting tip atomic force microscopy analysis of aluminum oxide barrier defects decorated by electrodeposition

We show that the electrodeposition of Ni80Fe20 on top of a thin aluminum ox ide barrier leads to particle growth occurring on preferential nucleation c enters. The particle sites are attributed to local defects in the aluminum oxide barrier. As a function of the thickness of the barrier, different gro wth modes can occur. For thinner barriers, new nucleation centers are creat ed during electrodeposition. The resistance of the defects, characterized b y conducting atomic force microscopy, ranges from less than 10(4) to greate r than 10(12) Omega. Various I(V) characteristics were also obtained, depen ding on the resistance of the defect. These results suggest that this exper imental technique could be a very interesting one with which to fabricate n anoconstrictions dedicated to ballistic magnetoresistance studies. (C) 2001 American Institute of Physics.