Abstract
The structure and magnetic properties of Co1-xPtx/SiO2 granular films with the Pt atomic content x varying from 0.42 to 0.71 have been investigated. It was found that the CoPt grains transform from disordered fee to the ideal ordered L 10 structure after annealing at 680°C. In the range of x = 0.42-0.60, the lattice parameter ratio a/c slightly varies from 0.965 to 0.979. For the Pt content x∼0.7, the superstructure exists but the lattice constant ratio is equal to 0.998. The coercivity dramatically increases from 1.8 to 9.1 kOe and then decreases to several hundred Oe while x increases from 0.42 to 0.71 for the grain size d ∼ 10 nm. We also found that the coercivity increases with the grain size. Our results show that the highly ordered fct structure, accompanied by the high crystalline anisotropy, is a prerequisite for the high coercivity, and the coercivity can be tailored by controlling either the composition or the grain size.
Original language | English |
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Pages (from-to) | 6947-6949 |
Number of pages | 3 |
Journal | Journal of Applied Physics |
Volume | 87 |
Issue number | 9 III |
DOIs | |
Publication status | Published - 2000 May 1 |
Event | 44th Annual Conference on Magnetism and Magnetic Materials - San Jose, CA, United States Duration: 1999 Nov 15 → 1999 Nov 18 |
ASJC Scopus subject areas
- Physics and Astronomy(all)