Title :
Alternative plasma-oxidized barriers for spin-polarized tunneling
Author :
Kant, C.H. ; Kohlhepp, J.T. ; Knechten, K. ; Swagten, H.J.M. ; de Jonge, W.J.M.
Author_Institution :
Dept. of Appl. Phys., Eindhoven Univ. of Technol., Netherlands
fDate :
7/1/2004 12:00:00 AM
Abstract :
We have obtained high-quality tunnel junctions with MgO barriers and superconducting Al bottom electrodes by sputter deposition and plasma oxidation. These junctions were used for spin-polarized tunneling measurements in which the Zeeman-split superconducting density of states is used to determine directly the tunneling spin polarization with Co and Fe top electrodes. Similar attempts with Ta2O5 barriers resulted in poor quality of the superconducting gap, with drastically reduced width, for both Al and V superconducting bottom electrodes.
Keywords :
Zeeman effect; diffusion barriers; electronic density of states; interface states; magnesium compounds; spin polarised transport; sputter deposition; superconducting energy gap; tunnelling magnetoresistance; Co-MgO-Al; Fe-MgO-Al; Ta2O5 barriers; Zeeman-split superconducting density of states; alternative plasma-oxidized barriers; high-quality tunnel junctions; plasma oxidation; spin-polarized tunneling measurements; sputter deposition; superconducting bottom electrodes; superconducting gap; tunneling spin polarization; Density measurement; Electrodes; Iron; Josephson junctions; Oxidation; Plasma density; Plasma measurements; Polarization; Sputtering; Tunneling; Spin polarization; tunneling;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2004.830627
