Magnetic domain imaging of Ni micro ring and micro dot array by photoelectron emission microscopy

Taichi Okuda, Hideyuki Kiwata, Takeshi Matsushima, Takanori Wakita, Ayumi Harasawa, Kanta Ono, Takayuki Kihara, Masaharu Oshima, Atsushi Yokoo, Toyohiko Kinoshita

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

The magnetic domain structures of Ni micro ring (the inner and outer diameters are changed in a micrometer region) and micro dot array with different shapes and with a small separation between dots were observed by the combined method of photoelectron emission microscopy and X-ray magnetic circular dichroism. For the micro rings with a large inner diameter, a flux-closure (FC) domain structure tends to appear more easily than for those with a small inner diameter. This means that the FC domain structure of the micro rings with a large inner diameter is energetically more stable than those of the micro rings with a small inner diameter and the disks. After applying an external pulsed magnetic field of about 40 mT in the in-plane direction, each domain structure switched to an almost perfect single-domain structure. Because of the absence of a central vortex core in the ring as compared with the disks, exchange energy decreases substantially. These phenomena are discussed along with the simulation results. For the micro dot array, the interaction between dots was directly observed. Particularly for the circular disks with a small diameter showing FC domains, no interaction is observed due to the lack of stray fields from each disk. On the other hand, dots with multi domain structures interacted. These types of information may provide us fundamental knowledge for designing high-density magnetic recording media.

Original languageEnglish
Pages (from-to)4179-4184
Number of pages6
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Volume43
Issue number7 A
DOIs
Publication statusPublished - Jul 1 2004
Externally publishedYes

Keywords

  • MCD
  • Magnetic domain
  • Mesoscopic structures
  • Microscopy
  • PEEM

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)

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