Magnetic tunnel junctions with single-crystal electrodes: A crystal anisotropy of tunnel magneto-resistance
Electrotechnical Laboratory - Tsukuba 305-8568, Japan
2 Joint Research Center for Atom Technology (JRCAT) Angstrom Technology Partnership (ATP) - Tsukuba 305-0046, Japan
3 JRCAT, National Institute for Advanced Interdisiplinary (NAIR) Tsukuba 305-8562, Japan
Accepted: 15 September 2000
A strong dependence of tunnel magnetoresistance (TMR) on the crystal orientation of ferromagnetic electrodes was confirmed experimentally. We studied the TMR of tunnel junctions with single-crystal Fe electrodes of different crystal orientations and found that the TMR ratio increased from 13% to 42% at 2K (8% to 26% at room temperature) when the crystal orientation was changed from (100) to (211). Such a TMR anisotropy could be explained in terms of the anisotropic spin polarization of Fe bulk and/or interface electronic states. The importance of the “momentum-filtering” effect of the tunnel barrier was also discussed.
PACS: 73.40.Gk – Tunneling / 73.40.Rw – Metal-insulator-metal structures / 75.70.Pa – Giant magnetoresistance
© EDP Sciences, 2000