Preparation and magnetic properties of CoPt and CoPt:Ag nanocluster films

Y. Xu, Z. G. Sun, Y. Qiang, D. J. Sellmyer

Research output: Contribution to journalArticlepeer-review

47 Scopus citations

Abstract

CoPt and CoPt:Ag nanocluster films have been prepared using a sputtering gas-aggregation cluster source. The cluster size can be controlled in a range from 3 to 8nm. CoPt cluster films are directly deposited onto Si or 7059 glass substrates. CoPt:Ag cluster films are deposited by co-sputtering or by a CoPt cluster layer with a Ag underlayer and an overlayer. Crystal structure, nanostructure and magnetic properties of the samples were characterized by X-ray diffraction, transmission electron microscopy, and magnetometry. The as-deposited cluster films contain the magnetically soft disordered FCC CoPt phase. Tetragonal L10 ordering is realized in the films annealed at a temperature above 650°C. The orientation of clusters is generally 〈111〉. The coercivity increases with increase of annealing temperature and annealing time, and very high in-plane and out-of-plane coercivities have been achieved in both CoPt and CoPt:Ag cluster films after annealing at a temperature of 700°C for 10min. The effect of Ag addition on the CoPt:Ag cluster films and the atomic ordering process in these films, and their relations to the hard magnetic properties, is discussed. The preparation of cluster films may provide a new method for fabrication of extremely high-density magnetic recording media.

Original languageEnglish (US)
Pages (from-to)164-170
Number of pages7
JournalJournal of Magnetism and Magnetic Materials
Volume266
Issue number1-2
DOIs
StatePublished - Oct 2003

Keywords

  • Cluster film
  • CoPt
  • High coercivity
  • L1 ordering
  • Nanocluster

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Preparation and magnetic properties of CoPt and CoPt:Ag nanocluster films'. Together they form a unique fingerprint.

Cite this