Magnetism of Cobalt Base Artificial Lattice Films

Abstract

The Co/Pd and Co/Pd artificial lattice films have attracted much interest by their special magnetization properties. We discussed the effect of the Pt, Pd layer thickness on the magnetic anisotropy, and we showed the effect of the hydrogen ion implantation on the magnetic properties of multi-layered films. The Co/Pt and Co/Pd multi-layered films were formed on Si(111) substrates with molecular beam epitaxy. We did structure analysis, magnetic domain analysis and magnetic properties evaluation with XRD, MFM and VSM, respectively. Among the series of films of 0.4 nm Co layer, XRD showed that the film of 1.0 nm Pt layer had a highest periodicity and that they had (111) plane orientation completely. The magnetic domain size reduced with the increase of the thickness of Pt layer. We found out that the coercivity decreased linearly as a function of the length of magnetic domain wall in the unit area. The result of VSM showed that the multi-layered films of Pt thickness of less than 2.8 nm had perpendicular magnetic anisotropy. The perpendicular anisotropy energy changed by the nonmagnetic layer thickness and had a maximum value for 0.4 nm Co 0.4 nm/nonmagnetic metal 1.0 nm multi-layered film. After hydrogen implantation into the films, XRD showed that the lattice spacing was swelled with hydrogen dose. Also, MFM observed that the magnetic domain size reduced with the increase of the hydrogen dose. The easy axis of magnetization changed from perpendicular to parallel in the plane with the increase of the hydrogen dose. After evacuation of hydrogen at 473 K, perpendicular anisotropy was partially recovered. This phenomenon suggested that the origin of magnetic anisotropy was mainly the lattice mismatch and distortion in the layer interface. But Co/Pd film was not recovered by this thermal treatment. This means that Pd made stable hydride and did not evacuate hydrogen at this temperature.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 2001
Accession Number
ADP012261

Entities

People

  • Kunihiko Taka
  • Masataka Masuda
  • Naoki Yoshitake
  • Shun Matsumoto
  • Yasunori Hayashi

Organizations

  • Kyushu University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Diffraction
  • Distortion
  • Domain Walls
  • Ion Implantation
  • Laboratory Magnetometers
  • Magnetic Anisotropy
  • Magnetic Domains
  • Magnetic Materials
  • Magnetic Properties
  • Materials
  • Materials Science
  • Optical Materials
  • Protons
  • Single Crystals
  • Spin-Orbit Interaction
  • X Rays
  • X-Ray Diffraction

Readers

  • Nanofabrication and Microfabrication.
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.
  • Thin Film Deposition Science.

Technology Areas

  • Space