Title :
Photoconductance in magnetic tunnel junctions
Author :
Koller, P.H.P. ; Vanhelmont, F.W.M. ; Coehoorn, R. ; de Jonge, W.J.M.
Author_Institution :
Dept. of Appl. Phys., Eindhoven Univ. of Technol., Netherlands
fDate :
9/1/2002 12:00:00 AM
Abstract :
The photoconductance of magnetic tunnel junctions has been studied in order to obtain directly determined values of the tunnel barrier height. Experiments for different types of junctions show that the presence of an aluminum layer close to the oxide barrier is crucial for the observation of a large photocurrent. For Ni80Fe20-based magnetic tunnel junctions, the effective barrier height increases with increasing magnetic layer thickness between the aluminum source layer and the aluminum oxide barrier. This trend is also visible in the barrier height determined from a Simmons fit to the current-voltage characteristics.
Keywords :
MIM structures; Permalloy; giant magnetoresistance; hot carriers; magnetic multilayers; photoconductivity; tunnelling; Fowler equation; Ni80Fe20; Simmons fit; current-voltage characteristics; effective barrier height; large photocurrent; magnetic layer thickness; magnetic tunnel junctions; magnetoconductance; photoconductance; tunnel barrier height; Aluminum; Electrodes; Electrons; Geometry; Iron; Magnetic tunneling; Oxidation; Photoconducting materials; Photoconductivity; Plasma materials processing;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2002.803171
