Effect of structure on the magnetic anisotropy ofL10FePt nanoparticles

Abstract

ABSTRACT. We carry out a systematic theoretical investigation of Magneto Crystalline Anisotropy (MCA) of L1 0 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 (DFT), 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 L1 0 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.

Ultrathin Scattering Spin Filter and Magnetic Tunnel Junction Implemented by Ferromagnetic 2D van der Waals Material

“…The maximum MAE, which is defined as the energy difference of the system with magnetization axis along the easy axis and perpendicular to it, is calculated to be 2.46 meV per cell, that is, 0.82 meV per Fe atom. This value is about two orders of magnitude larger than the MAE of Fe, Co, and Ni, and is about one third of the MAE of FePt alloy 42. The result suggests that single‐layer FGT is promising for magnetic storage and spintronic applications.…”

Determination of Magneto-crystalline Anisotropy Energy (MAE) Of ordered L10CoPt and FePt nanoparticles

“…A lot of efforts have been devoted to explore the physics of tiny structure for magnetic materials that can help to utilize its desirable properties [1][2][3]. In recent years, applications of magnetic nanoparticles have arisen, particularly those that have a high anisotropic energy [1,[4][5][6][7].…”

“…In recent years, applications of magnetic nanoparticles have arisen, particularly those that have a high anisotropic energy [1,[4][5][6][7]. Because of their potential applications such as data storage, optical filters, and biomedical applications, some of magnetic nanoparticles gain crucial importance [8][9][10].…”

Vibrational properties and stability of FePt nanoalloys

“…The Monte Carlo simulations show that melting temperatures of FePt NPs are much lower than the bulk phase-transition temperature (1572 K) and decrease with the particle size reduction [40]. The structural order and magnetic properties of FePt nanoalloys with various morphologies were studied previously within the DFT calculations [41][42][43][44]. Recently, we have investigated the influence of chemical composition on the stability of FePt icosahedra using the ab initio molecular dynamics (MD) simulations [45].…”