Enhancement of coercivity in nanometer-size CoPt crystallites

S. H. Liou, S. Huang, E. Klimek, R. D. Kirby, Y. D. Yao

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In this study, we showed that a magnetic coercivity (Hc) as high as 37 kOe was obtained in a CoPt thin film that contains separated nanometer-size CoPt crystallites. We prepared CoPt thin films with thicknesses of 5 and 175 nm by magnetron sputtering. After annealing in an Ar/H2 atmosphere at temperatures from 650 to 750°C for 3-12 h, we measured the magnetic properties and found that magnetic Hc relates to annealing temperature, annealing time and film thickness. From atomic force microscopy and magnetic force microscopy studies, the magnetic single domain size of CoPt is in the range of 100-200 nm. The high Hc is likely due to the well-separated nanometer-size crystallites and the well-ordered fct phase of CoPt alloy.

Original languageEnglish (US)
Pages (from-to)4334-4336
Number of pages3
JournalJournal of Applied Physics
Issue number8 II A
StatePublished - Apr 15 1999


ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Liou, S. H., Huang, S., Klimek, E., Kirby, R. D., & Yao, Y. D. (1999). Enhancement of coercivity in nanometer-size CoPt crystallites. Journal of Applied Physics, 85(8 II A), 4334-4336.