Influence of pinholes on MgO-tunnel junction barrier parameters obtained from current-voltage characteristics.
Magnetic tunnel junctions (MTJs) with thin barriers are already used as read sensors in recording media. However, the presence of pinholes across such few A thick barriers cannot be excluded and one needs to investigate their effect on the MTJ-transport properties. By applying large electrical currents we could change the electrical resistance of the studied MgO MTJs (due to pinhole-size variations), and study how pinholes influence the barrier parameters (thickness t and height phi) obtained by fitting current-voltage characteristics to Simmons' model. We found that, with decreasing resistance, the barrier thickness (height) decreases (increases). These results were well reproduced by a model of parallel-resistances, allowing us to estimate pinhole-free barrier parameters.
Ventura
J
J
IN, IFIMUP Unit, Rua do Campo Alegre, 687, 4169-007, Porto, Portugal.
Teixeira
J M
JM
Araujo
J P
JP
Sousa
J B
JB
Ferreira
R
R
Freitas
P P
PP
Langer
J
J
Ocker
B
B
Maass
W
W