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Related papers: Multiscale modeling of ultrafast element-specific …

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Element specific ultrafast demagnetization was studied in Fe$_{1-x}$Ni$_{x}$ alloys, covering the concentration range between $0.1<x<0.9$. For all compositions, we observe a delay in the onset of Ni demagnetization relative to the Fe…

We present a micromagnetic formulation for modeling the magnetization dynamics and thermal equilibrium in ferrimagnetic materials at low and elevated temperatures. The formulation is based on a mean field approximation (MFA). In this…

Materials Science · Physics 2021-11-30 Marco Menarini , Vitaliy Lomakin

We study phenomenologically on the basis of two bilinearly coupled Heisen- berg models the phase diagram of some ferrimagnetic substances. Calculations are performed with the help of Landau energy obtained through applying the…

Other Condensed Matter · Physics 2018-08-14 Hassan Chamati , Diana V. Shopova

We report about element specific measurements of ultrafast demagnetization and magnetization precession damping in Permalloy (Py) thin films. Magnetization dynamics induced by optical pump at $1.5$eV is probed simultaneously at the…

Materials Science · Physics 2023-03-29 A. Maghraoui , F. Fras , M. Vomir , Y. Brelet , V. Halté , J. Y. Bigot , M. Barthelemy

Ultrafast laser-induced magnetic switching in rare earth, transition metal ferrimagnetic alloys has recently been reported to occur by ultrafast heating alone. Using atomistic simulations and a ferrimagnetic Landau-Lifshitz-Bloch formalism,…

Materials Science · Physics 2015-06-05 U. Atxitia , T. Ostler , J. Barker , R. F. L. Evans , R. W. Chantrell , O. Chubykalo-Fesenko

Recent experimental findings revealed an exceptionally diverse laser-induced spin dynamics tunable by magnetic field ($H$) and temperature ($T$) in ferrimagnetic Gd/FeCo multilayers, however the theoretical picture of these processes…

Precise modeling of the magnetization dynamics of nanoparticles with finite size effects at fast varying temperatures is a computationally challenging task. Based on the Landau-Lifshitz-Bloch (LLB) equation we derive a coarse grained model…

Materials Science · Physics 2019-08-07 Christoph Vogler , Claas Abert , Florian Bruckner , Dieter Suess

The ultra-fast magnetisation relaxation rates during the laser-induced magnetisation process are analyzed in terms of the Landau-Lifshitz-Bloch (LLB) equation for different values of spin $S$. The LLB equation is equivalent in the limit $S…

Materials Science · Physics 2015-05-20 U. Atxitia , O. Chubykalo-Fesenko

Magnetoelasticity plays a crucial role in numerous magnetic phenomena, including magnetocalorics, magnon excitation via acoustic waves, and ultrafast demagnetization/Einstein-de Haas effect. Despite a long-standing discussion on…

Experimental observations of the ultrafast (less than 50 fs) demagnetization of Ni have so far defied theoretical explanations particularly since its spin-flipping time is much less than that resulting from spin-orbit and electron-lattice…

Strongly Correlated Electrons · Physics 2020-07-08 Shree Ram Acharya , Volodymyr Turkowski , Guo-ping Zhang Talat S. Rahman

In this letter, we provide a microscopic model for the ultrafast remagnetization of atomic moments already quenched above Stoner-Curie temperature by a strong laser fluence. Combining first principles density functional theory, atomistic…

Materials Science · Physics 2015-06-11 Raghuveer Chimata , Anders Bergman , Lars Bergqvist , Biplab Sanyal , Olle Eriksson

We study the ultrafast demagnetization dynamics of LnRh$_2$Si$_2$ (Ln $=$ Pr, Nd, Sm, Gd, Tb, Dy, Ho) antiferromagnets (AFM) after excitation by a laser pulse, using a combination of density functional theory and atomistic spin and…

The calculation of interatomic magnetic exchange interactions entering the Heisenberg model from the standpoint of the density functional theory (DFT) is outlined for two Fe-based molecular magnets: a trinuclear complex with a Schiff base…

Materials Science · Physics 2007-05-23 A. V. Postnikov , G. Bihlmayer , S. Bluegel

We study the demagnetization dynamics of the fully compensated half-metallic ferrimagnet Mn$_2$Ru$_x$Ga. While the two antiferromagnetically coupled sublattices are both composed of manganese, they exhibit different temperature dependencies…

Materials Science · Physics 2021-01-18 G. Bonfiglio , K. Rode , G. Y. P. Atcheson , P. Stamenov , J. M. D. Coey , A. V. Kimel , Th. Rasing , A. Kirilyuk

Both helicity-independent and helicity-dependent all-optical switching processes driven by single ultrashort laser pulse have been experimentally demonstrated in ferrimagnetic alloys as GdFeCo. Although the switching has been previously…

Mesoscale and Nanoscale Physics · Physics 2022-03-30 V. Raposo , F. García-Sánchez , U. Atxitia , E. Martínez

Because of large spatial separation of the Mn atoms in Heusler alloys the Mn 3d states belonging to different atoms do not overlap considerably. Therefore an indirect exchange interaction between Mn atoms should play a crucial role in the…

Materials Science · Physics 2009-11-13 E. Sasioglu , L. M. Sandratskii , P. Bruno

Magnetic frustration in ferromagnetic metallic systems is unusual due to the long-range and symmetric nature of the exchange interactions. In this work we prove that it is possible to obtain a highly frustrated ferromagnetic phase in a…

Atomistic spin model simulations are immensely useful in determining temperature dependent magnetic prop- erties, but are known to give the incorrect dependence of the magnetization on temperature compared to exper- iment owing to their…

Mesoscale and Nanoscale Physics · Physics 2015-05-12 R. F. L. Evans , U. Atxitia , R. W. Chantrell

By using a multiscale approach based on first-principles density functional theory combined with atomistic spin dynamics, we investigate the electronic structure and magnetization dynamics of an inverse Heusler and a Heusler compound and…

Materials Science · Physics 2018-02-21 R. Chimata , E. K. Delczeg-Czirjak , J. Chico , M. Pereiro , B. Sanyal , O. Eriksson , D. Thonig

An extended atomistic spin model allowing for studies of the finite temperature magnetic properties of alloys is proposed. The model is obtained by extending the Heisenberg Hamiltonian via a parameterization from a first principles basis,…

Computational Physics · Physics 2017-06-07 Fan Pan , Jonathan Chico , Anna Delin , Anders Bergman , Lars Bergqvist
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