Effect Of Structure On The Magnetic Anisotropy Of L10 Fept Nanoparticles

Abstract

We carry out a systematic theoretical investigation of magnetocrystalline anisotropy (MCA) of L10 FePt clusters with alternating Fe and Pt planes along the (001) direction. The clusters studied contain 30-484 atoms. We calculate the structural relaxation and magnetic moment of each cluster by using ab initio spin-polarized density functional theory, and the MCA with both the self-consistent direct method and the torque method. We find the two methods give equivalent results for all the structures examined. We find that bipyramidal clusters whose central layer is Pt have higher MCA than their same-sized counterparts whose central layer is Fe. This results from the fact that the Pt atoms in such configurations are coordinated with more Fe atoms than in the latter. By thus participating in more instances of hybridization, they contribute higher orbital moments to the overall MCA of the unit. Our findings suggest that by properly tailoring the structure one can avoid encapsulating the FePt L10 nanoparticles, as has been proposed earlier, to protect a high and stable magnetic anisotropy. Additionally, using a simple model to capture the thermal behavior, we predict that a five-layered nanoparticle with approximately 700 atoms can be expected to be useful in magnetic recording applications at room temperature.

Publication Date

8-13-2015

Publication Title

Physical Review B - Condensed Matter and Materials Physics

Volume

92

Issue

5

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1103/PhysRevB.92.054424

Socpus ID

84939856560 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84939856560

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