2022/07/24 by Thanh-Binh Nguyen, Sergiu Ruta, Nguyen, Binh Thanh +7
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic Properties and Applications #Magnetic properties of thin films #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Surface and Thin Film Phenomena
paper · doi:10.48550/arxiv.2207.11831
openalex publication_date 2022/07/24 · openalex created_date 2022/07/28 · openalex updated_date 2026/07/28
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.