Magnetization chirality of Ni-Fe and Ni-Fe/Mn-Ir asymmetric ring dots for high-density memory cells

Isao Sasaki, Ryoichi Nakatani, Tetsuo Yoshida, Keiichi Otaki, Yasushi Endo, Yoshio Kawamura, Masahiko Yamamoto, Takashi Takenaga, Sunao Aya, Takeharu Kuroiwa, Sadeh Beysen, Hiroshi Kobayashi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)

Abstract

The magnetic configurations of Ni-20at%Fe/Hf and Ta/Ni-20at%Fe/Mn-28at%Ir/ Ni-20at%Fe/Ta asymmetric ring dots have been studied. Recently, we proposed that asymmetric ring structures are suitable for magnetic memory cells and then demonstrated that asymmetric structures can control the chirality of the vortical magnetization with in-plane fields. The investigation of the Ni-20at%Fe(20 nm)/Hf(5 nm) asymmetric ring dots for free layers in magnetic memory cells demonstrated that switching fields cause a transition from the vortex state to the onion state that increases as the ring width decreases from 410 nm to 210 nm since a narrow ring has a higher demagnetizing field than that of a wide ring during the transition. The investigation of the Ta(3 nm)/Ni-20at%Fe(15 nm)/Mn-28at%Ir(10 nm)/Ni-20at%Fe(3 nm)/Ta(5 nm) asymmetric ring dots for the pinned layers in magnetic memory cells demonstrated that the chirality of the vortical magnetization is pinned regardless of the magnetic field direction.

Original languageEnglish
Title of host publicationAdvanced Structural and Functional Materials Design - Proceedings of the International Symposium on Advanced Structural and Functional Materials Design, 2004
PublisherTrans Tech Publications Ltd
Pages171-176
Number of pages6
ISBN (Print)0878499962, 9780878499960
DOIs
Publication statusPublished - 2006
Externally publishedYes
EventInternational Symposium on Advanced Structural and Functional Materials Design, 2004 - Osaka, Japan
Duration: 2004 Nov 102004 Nov 12

Publication series

NameMaterials Science Forum
Volume512
ISSN (Print)0255-5476
ISSN (Electronic)1662-9752

Other

OtherInternational Symposium on Advanced Structural and Functional Materials Design, 2004
Country/TerritoryJapan
CityOsaka
Period04/11/1004/11/12

Keywords

  • Magnetic force microscopy
  • Magnetic memory
  • Magnetization reversal
  • Ring dots

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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