MR ratio enhancement by NOL current-confined-path structures in CPP spin valves

Hideaki Fukuzawa, Hiromi Yuasa, Susumu Hashimoto, Katsuhiko Koi, Hitoshi Iwasaki, Masayuki Takagishi, Yoichiro Tanaka, Masashi Sahashi

Research output: Contribution to journalArticlepeer-review

93 Citations (Scopus)

Abstract

We have compared the magnetoresistance (MR) performance of current-confined-path (CCP) current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) spin valve films with a nano-oxide-layer (NOL), made between natural oxidation (NO) and ion-assisted oxidation (IAO). For the NO, an MR ratio was only 1.5% at an RA of 370 mωμm 2 , whereas for the IAO, an MR ratio was greatly increased to 5.4% at an RA of 500 mωμm 2 . Fitted data by the Valet-Fert model showing larger MR enhancement effect by the IAO is explained by the improvement of the metal-purity of the Cu inside the CCP structure. By further improvement of metal-purity of the Cu, a large MR ratio of more than 30% can be expected at a small RA of 300 mωμm 2 . The CCP-CPP spin valve film is a promising candidate for realizing high-density recording heads for 200 to 400-Gbpsi recording.

Original languageEnglish
Pages (from-to)2236-2238
Number of pages3
JournalIEEE Transactions on Magnetics
Volume40
Issue number4 II
DOIs
Publication statusPublished - 2004 Jul 1

Keywords

  • CPP-GMR
  • Current-confined-path
  • Oxides
  • Spin valves

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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