Ordering and grain growth kinetics in CoPt thin films

Book · Tue Dec 31 04:00:00 EST 1996

OSTI ID:479317

Ristau, R A; Barmak, K; Hess, D W ^[1]; Coffey, K R; Parker, M A; Howard, J K ^[2]

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1. Lehigh Univ., Bethlehem, PA (United States)
2. IBM, San Jose, CA (United States). Storage Systems Div.

Ordering and grain growth have been studied in a 10 nm thick CoPt alloy film of equiatomic composition annealed in the temperature range 550--700 C by quantifying ordered domain size, volume fraction ordered, grain size, and grain size distribution. Ordering occurs by nucleation and growth of L1{sub 0} ordered domains, with a mean size of 3 nm at 550 C and 19 nm at 700 C. The volume percent ordered shows a dramatic increase from < 1% to approximately 28% between the two extremes of annealing temperature. The mean grain size of the as-deposited films is 5 nm and the entire film is face-centered cubic. Upon annealing in the temperature range 550--600 C, the mean grain size reaches a stagnation limit of 27 nm and the grain size distribution is log-normal. Grain growth resumes beyond 600 C and the mean grain size reaches as high as 55 nm at 700 C. The increase in the coercivity of the annealed films follows the increase in the ordered fraction more closely than the increase in grain size. The shape of the M-H loop shows evidence of coupling between the magnetically hard (ordered) and soft (disordered) regions.

• Sponsoring Organization: National Science Foundation, Washington, DC (United States)
• OSTI ID: 479317
• Report Number(s): CONF-951155--; ISBN 1-55899-301-0
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
COBALT ALLOYS
COERCIVE FORCE
EXPERIMENTAL DATA
GRAIN GROWTH
GRAIN SIZE
MAGNETIC PROPERTIES
ORDER PARAMETERS
PLATINUM ALLOYS
RECORDING SYSTEMS
SPUTTERING
THIN FILMS