Wh. Rippard et al., Ballistic current transport studies of ferromagnetic multilayer films and tunnel junctions (invited), J APPL PHYS, 89(11), 2001, pp. 6642-6646
Three applications of ballistic electron microscopy are used to study, with
nanometer-scale resolution, the magnetic and electronic properties of magn
etic multilayer thin films and tunnel junctions. First, the capabilities of
ballistic electron magnetic microscopy are demonstrated through an investi
gation of the switching behavior of continuous Ni80Fe20/Cu/Co trilayer film
s in the presence of an applied magnetic field. Next, the ballistic, hot-el
ectron transport properties of Co films and multilayers formed by thermal e
vaporation and magnetron sputtering are compared, a comparison which reveal
s significant differences in the ballistic transmissivity of thin film mult
ilayers formed by the two techniques. Finally, the electronic properties of
thin aluminum oxide tunnel junctions formed by thermal evaporation and spu
tter deposition are investigated. Here the ballistic electron microscopy st
udies yield a direct measurement of the barrier height of the aluminum oxid
e barriers, a result that is invariant over a wide range of oxidation condi
tions. (C) 2001 American Institute of Physics.