Abnormal reduction of coercivity on magnetic cobalt-platinum alloy films

C. W. Su*, C. S. Shern

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Ultrathin Co-Pt alloy films as substrate were studied by the surface magneto-optical Kerr effect. As the growth of Ni, the films show uniquely high polar Kerr responses without any in-plane signals. The coercivity decreased until the thickness of Ni film was higher than 5 ML. A new surface structure was discovered at 7-10 ML Ni/Co-Pt films by the low-energy electron diffraction. Interestingly, polar Kerr signal and coercivity of the 10 ML Ni/Co-Pt(1 1 1) template film reduced rapidly as Co films were further deposited onto only about 1-2 ML. Then the films show a canted magnetization with a rollback hysteresis in the polar configuration during the growth of Co. Coercivity of the 7 ML Co/Ni/Co-Pt film was found unusually down to almost 100 Oe.The corresponding magic number at around 7 ML of Co in the abnormal reduction of coercivity may be attributed to the cluster formations of Co.

Original languageEnglish
Pages (from-to)e234-e237
JournalJournal of Magnetism and Magnetic Materials
Issue number2 SPEC. ISS.
Publication statusPublished - 2006 Aug


  • Cobalt-platinum alloys
  • Coercivity
  • Nickel-platinum alloys
  • Surface magneto-optical Kerr effect
  • Ultrathin films

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


Dive into the research topics of 'Abnormal reduction of coercivity on magnetic cobalt-platinum alloy films'. Together they form a unique fingerprint.

Cite this