Effect of oxygen exposure on the magnetic properties of ultrathin Co/Ge(1 1 1) films

J. S. Tsay, H. W. Chang, Y. L. Chiou, K. T. Huang, W. Y. Chan, Y. D. Yao

Research output: Contribution to journalArticle

Abstract

Influences of oxygen exposure on the magnetic properties of Co/Ge(1 1 1) ultrathin films have been investigated by surface magneto-optic Kerr effect technique. As the oxygen exposure increases on Co/Ge(1 1 1) films, their magnetic properties could be modified. As an example for 15 ML Co/Ge(1 1 1) films, the coercivity increases from 730 to 920 Oe and the remanence Kerr intensity is reduced for 500 Langmuir (L) of oxygen exposure. Corresponding compositions analyzed by Auger electron spectroscopy measurement shows that the amount of oxygen on the surface layers increases with increasing the oxygen exposure time. Oxygen distributes on the topmost layers of the film. The adsorbed oxygen influences the electronic density of states of Co and results in the changes of the magnetic properties. Besides, the appearance of O/Co/Ge interface could modify the stress anisotropy, and as a result the coercivity of ultrathin Co/Ge(1 1 1) film is enhanced.

Original languageEnglish
Pages (from-to)e68-e70
JournalJournal of Magnetism and Magnetic Materials
Volume304
Issue number1
DOIs
Publication statusPublished - 2006 Sep 1

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Keywords

  • Cobalt
  • Germanium
  • Oxygen exposure
  • Surface magneto-optic Kerr effect
  • Ultrathin films

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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