Controllable Remanent States on Microstructured Magnetic Tunnel Junction Rings

Author

Chen, C.C. ; Chao, C.T. ; Kuo, C.Y. ; Horng, Lance ; Wu, Teho ; Chern, G. ; Huang, C.Y. ; Isogami, S. ; Tsunoda, M. ; Takahashi, M. ; Wu, J.C.

Author_Institution

Taiwan SPIN Res. Center, Nat. Changhua Univ. of Educ.

Volume

43

Issue

6

fYear

2007

fDate

6/1/2007 12:00:00 AM

Firstpage

2824

Lastpage

2826

Abstract

Controllable remanent states have been studied on the microstructured magnetic tunnel junction (MTJ) rings through magnetoresistance measurements. These rings were designed accordingly with an outer/inner diameter of 2/1 and 1/0.5 mum to reveal two and one metastable states, respectively, during the magnetization reversal process on the free layer. The distinct magnetoresistance levels based on the tunneling magnetoresistance effect are associated with the relative alignment of magnetization of free layer and pinned layer. As a result, four and three controllable remanent magnetic states on the free layer were manipulated by ramping external magnetic fields, applied in the biasing direction, with various field ranges, giving rise to four and three stable magnetoresistance values at zero field. These results may provide a great potential in magnetic multibit memory applications using ring-shaped cells

Keywords

aluminium compounds; copper; iridium alloys; iron alloys; magnetic multilayers; manganese alloys; nickel alloys; remanence; rings (structures); silicon; silicon compounds; tantalum; tunnelling magnetoresistance; 0.5 mum; 1 mum; 2 mum; Si-SO₂-Ta-Cu-NiFe-CoFe-AlN; magnetic multibit memory; magnetization reversal; metastable states; microstructured magnetic tunnel junction rings; remanent states; ring-shaped cells; tunneling magnetoresistance; Chaos; Magnetic fields; Magnetic sensors; Magnetic tunneling; Magnetization reversal; Metastasis; Random access memory; Resists; Shape control; Tunneling magnetoresistance; Magnetic tunneling junction (MTJ); magnetoresistance; multibit application; ring-shaped cells;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2007.894206

Filename

4202665