Magnetoelastically induced perpendicular magnetic anisotropy and perpendicular exchange bias of CoO/CoPt multilayer films

Lei Guo, Yue Wang, Jian Wang, Shinji Muraishi, Takumi Sannomiya, Yoshio Nakamura, Ji Shi

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Abstract The effects of magnetoelastically induced perpendicular magnetic anisotropy (PMA) on perpendicular exchange bias (PEB) have been studied in [CoO5nm/CoPt5nm]5 multilayer films. After deposition at room temperature, [CoO5nm/CoPt5nm]5 multilayer films were post-annealed at 100°C, 250°C, 300°C and 375°C for 3 h. In-plane tensile stress of CoPt layer was calculated by sin2φ method, and we found it increased gradually upon annealing from 0.99 GPa (as-deposited) up to 3.02 GPa (300°C-annealed). As to the magnetic property, significant enhancement of PMA was achieved in [CoO5nm/CoPt5nm]5 multilayer films after annealing due to the increase of CoPt layer in-plane tensile stress. With the enhancement of magnetoelastically induced PMA, great improvement of PEB was also achieved in [CoO5nm/CoPt5nm]5 multilayer films, which increased from 130 Oe (as-deposited) up to 1060 Oe (300°C-annealed), showing the same change tendency as PMA and the strong correlation with CoPt layer in-plane tensile stress. We consider it is the increase of CoPt layer in-plane tensile stress that leads to the enhancement of CoPt layer PMA, which is favorable for the spins in CoPt layer aligning to a more perpendicular direction. And thus the enhanced PMA with more perpendicular spins alignment in CoPt layer results in the improved PEB in [CoO5nm/CoPt5nm]5 multilayer films through enhanced perpendicular spins coupling at CoO/CoPt interfaces.

Original languageEnglish
Article number60371
Pages (from-to)349-353
Number of pages5
JournalJournal of Magnetism and Magnetic Materials
Volume394
DOIs
Publication statusPublished - 2015 Jul 14

Keywords

  • CoO/CoPt multilayer film
  • Magnetoelastic effect
  • Perpendicular exchange bias
  • Perpendicular magnetic anisotropy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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