Polycrystalline CPP-GMR devices using <001> textured Co2Fe(Ga0.5Ge0.5) Heusler alloy layer and conductive Mg0.5Ti0.5Ox buffer layer

Y. Du, T. Furubayashi, Y. Takahashi, Y. Sakuraba, K. Hono

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

Abstract

Current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) devices with Co-based Heusler alloys have recently drawn considerable attention due to their potential application as read sensors for ultrahigh density magnetic recording.1,2,3,4 With a non-magnetic Ag spacer layer, the resistance change-area product (ΔRA) of epitaxial pseudo spin valves (PSVs) on single crystalline (001) MgO substrates has exceeded 10 mΩ μm2 by using quaternary ferromagnetic (FM) Heusler alloys such as Co2Fe(Ga0.5Ge0.5) (CFGG) and Co2Fe0.4Mn0.6Si (CFMS). From a practical point of view, however, we need to develop CPP-GMR sensors with polycrystalline thin films at relatively low annealing temperatures (<400°C). Our previous work on <001> textured polycrystalline CPP-GMR using MgO buffer layer showed favorable device thermal stability and moderate ΔRA of 5.8 mΩ μm2 at 400°C was obtained. Nevertheless, it is not industrially viable because MgO as an insulator cannot be used for the fabrication of the actual CPP-GMR sensors. In this work, we report the CPP-GMR properties and microstructure of PSV devices using <001> textured FM Heusler layer CFGG and Ag spacer with a conductive buffer layer Mg0.5Ti0.5Ox (MTO)6 deposited on an chemically-mechanically polished (CMP) Ta/Cu/Ta electrode on thermally oxidized Si substrates. Relatively large ΔRA of 6.6 mΩ μm2 and desirable interfacial smoothness make it a promising candidate for actual read head design.

Original languageEnglish
Title of host publication2015 IEEE International Magnetics Conference, INTERMAG 2015
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9781479973224
DOIs
Publication statusPublished - 2015 Jul 14
Externally publishedYes
Event2015 IEEE International Magnetics Conference, INTERMAG 2015 - Beijing, China
Duration: 2015 May 112015 May 15

Publication series

Name2015 IEEE International Magnetics Conference, INTERMAG 2015

Other

Other2015 IEEE International Magnetics Conference, INTERMAG 2015
CountryChina
CityBeijing
Period15/5/1115/5/15

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering
  • Surfaces, Coatings and Films

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