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

Volume

40

Issue

4

fYear

2004

fDate

7/1/2004 12:00:00 AM

Firstpage

2308

Lastpage

2310

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;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2004.830627

Filename

1325487