Out- versus in-plane magnetic anisotropy of Fe and Co nanocrystals
Abstract
The crucial issue in exploring ultimate density data storage is magnetocrystalline anisotropy energy (MAE) which originates from spin-orbit coupling. We report tight-binding and first-principles calculations of MAE of bcc-Fe and fcc-Co nanocrystals in the form of truncated square pyramids. Such nanocrystals can be grown experimentally on SrTiO3 with a remarkable control of their size and structure. For both elements, the total MAE of free nanocrystals is largely dominated by (001) facets resulting in out-of-plane or in-plane easy axis for Fe or Co, respectively. As a consequence, in Co nanocrystals the spin moment is allowed to rotate almost freely (with a very low in-plane anisotropy barrier) in the easy basal plane while Fe nanocrystals have a high uniaxial anisotropy which makes them much better potential candidates for magnetic storage devices. Next, our preliminary results show that the MAE of Fe and Co nanocrystals deposited on SrTiO3 can be significantly altered at the interface: in particular, clear out-of-plane MAE for Fe should be preserved, while for Co the situation is more complex.
Supported by ERC Grant No. 259297.- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2015
- Bibcode:
- 2015APS..MARQ30007L