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arXiv · 2207.11831

Influence of the Finite-size Effects on the Curie Temperature of L10-FePt

Binh Thanh Nguyen·Sergiu Ruta·Ondrej Hovorka·Richard. F. L. Evans·Roy. W. Chantrell
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Abstract

We employ an atomistic model using a nearest-neighbor Heisenberg Hamiltonian exchange to study computationally the dependence of the Curie temperature of L10-FePt on finite-size and surface effects in Heat-assisted Magnetic Recording (HAMR) media. We demonstrate the existence of a size threshold at 3.5nm below which the impact of finite-size effects start to permeate into the center of the grains and contribute to the reduction of the Curie temperature. We find a correlation between the Curie temperature and the percentage of atomistic bonds lost on the surface as a function of grain size, which can be extended to apply to not only L10-FePt but also generic magnetic systems of any crystal structure. The investigation gives insight into finite-size effects which, because the inevitable grain size dispersion leads to an irreducible contribution to a dispersion of the Curie temperature, has been predicted to be a serious limitation of HAMR.

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Binh Thanh Nguyen, Sergiu Ruta, Ondrej Hovorka, Richard. F. L. Evans, Roy. W. Chantrell. 2022-07-24. Influence of the Finite-size Effects on the Curie Temperature of L10-FePt. https://arxiv.org/abs/2207.11831

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