Title :
Low resistance spin-dependent tunneling junctions with naturally oxidized tunneling barrier
Author :
Sin, K. ; Mao, M. ; Chien, C. ; Funada, S. ; Miloslavsky, L. ; Tong, H.C. ; Gupta, S.
Author_Institution :
Read-Rite Corp., Freemont, CA, USA
fDate :
9/1/2000 12:00:00 AM
Abstract :
We investigated the effect of aluminum thickness on RA (resistance area product) and MR ratio in spin-dependent tunnel junctions. Very low RA values below 40 Ω μm2 and a maximum MR ratio of 6% were obtained in Ni81Fe19/Al2O3 /Ni81Fe19 tunneling junctions fabricated using natural oxidation of aluminum. The MR ratio significantly increased with use of Co90Fe10 electrodes. Using natural oxidation of 6 Å aluminum, RA and MR ratio of these junctions are ~50 Ω μm2 and ~28%, respectively. The MR ratio and the junction resistance strongly depend on the aluminum thickness. The optimum thickness of aluminum is 6-7 Å fur natural oxidation
Keywords :
MIM structures; Permalloy; alumina; ferromagnetic materials; giant magnetoresistance; magnetic heads; magnetic multilayers; oxidation; spin valves; tunnelling; 6 to 7 angstrom; Co90Fe10; MR ratio; Ni81Fe19-Al2O3-Ni 81Fe19; aluminum thickness effect; giant magnetoresistance; low resistance junctions; magnetic RAM; magnetic heads; naturally oxidized tunneling barrier; optimum thickness; resistance area product; spin-dependent tunneling junctions; Aluminum; Electrodes; Iron; Magnetic heads; Magnetic tunneling; Optical films; Oxidation; Silicon compounds; Sputtering; Tunneling magnetoresistance;
Journal_Title :
Magnetics, IEEE Transactions on
