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The European Physical Journal B

, Volume 59, Issue 4, pp 471–474 | Cite as

Spin torque transfer structure with new spin switching configurations

  • J.-P. WangEmail author
  • H. Meng
Topical Issue on New Trends in Spin Transfer Physics

Abstract.

Spin torque transfer structures with new spin switching configurations are proposed, fabricated and investigated in this paper. The non-uniform current-induced magnetization switching is implemented based on both GMR and MTJ nano devices. The proposed new spin transfer structure has a hybrid free layer that consists of a layer with conductive channels (magnetic) and non-conductive matrix (non-magnetic) and traditional free layer(s). Two mechanisms, a higher local current density by nano-current-channels and a non-uniform magnetization switching (reversal domain nucleation and growth) by a magnetic nanocomposite structure, contribute in reducing the switching current density. The critical switching current density for the new spin transfer structure is reduced to one third of the typical value for the normal structure. It can be expected to have one order of magnitude or more reduction for the critical current density if the optimization of materials and fabrication processes could be done further. Meanwhile, the thermal stability of this new spin transfer structure is not degraded, which may solve the long-standing scaling problem for magnetic random access memory (MRAM). This spin transfer structure, with the proposed and demonstrated new spin switching configurations, not only provides a solid approach for the practical application of spin transfer devices but also forms a unique platform for researchers to explore the non-uniform current-induced switching process.

PACS.

72.25.-b Spin polarized transport 72.25.Ba Spin polarized transport in metals 73.63.-b Electronic transport in nanoscale materials and structures 75.47.-m Magnetotransport phenomena; materials for magnetotransport 

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Copyright information

© EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2007

Authors and Affiliations

  1. 1.The Center for Micromagnetics and Information Technologies (MINT) & Department of Electrical & Computer EngineeringUniversity of MinnesotaMinneapolisUSA

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