Magnetoelasticity plays a crucial role in numerous magnetic phenomena, including magnetocalorics, magnon excitation via acoustic waves, and ultrafast demagnetization, or the Einstein–de Haas effect. Despite long-standing discussion on anisotropy-mediated magnetoelastic interactions of relativistic origin, exchange-mediated parameters within an atomistic framework have only recently begun to be investigated. As result, many their behaviors values for real materials remain poorly understood....

Abstract Despite decades of research, the role lattice and its coupling to magnetisation during ultrafast demagnetisation processes is still not fully understood. Here we report on studies both explicit implicit effects laser induced bcc Fe fcc Co. We do this using atomistic spin- dynamics simulations following a heat-conserving three-temperature model. show that type Langevin-based simulation able reproduce observed trends magnetization Co Fe. The parameters used in our models are all...

Magnetic skyrmions are prime candidates for the next generation of spintronic devices. Skyrmions and other topological magnetic structures known to be stabilized by Dzyaloshinskii-Moriya interaction (DMI) that occurs when inversion symmetry is broken in thin films. Here, we show first-principles calculations atomistic spin dynamics simulations metastable skyrmionic states can also found nominally symmetric multilayered systems. We demonstrate this correlated with large enhancement DMI...

Abstract To develop new devices based on synthetic ferrimagnetic heterostructures, understanding the material’s physical properties is pivotal. Here, induced magnetic moment (IMM), exchange coupling, and spin textures are investigated in Pt(1 nm)/Co(1.5 nm)/Gd(1 nm) multilayers using a multiscale approach. The magnitude direction of IMM interpreted framework both X-ray circular dichroism density functional theory. transferred by Co across Gd paramagnetic thickness leads to nontrivial flipped...

Multireservoir models are widely used for modeling and interpreting ultrafast magnetization dynamics. Here we introduce an alternative formulation to existing three-temperature the treatment of spin, electron, lattice temperatures in dynamics simulations. In contrast most calculations energy transfer between reservoirs these types simulations, heat distribution spin subsystems is evaluated during simulation instead being calculated a priori. The model applied investigate demagnetization...

The structural phase transition path from the low-temperature polar structure up to highest symmetric in hybrid improper ferroelectric ${\mathrm{Ca}}_{3}{\mathrm{Mn}}_{2}{\mathrm{O}}_{7}$ compound is here investigated at atomic scale. Measurements using perturbed angular correlation local probe technique are combined with ab initio electronic calculations observe evolution of electric field gradient parameters $\mathrm{Ca}$ site within 10--1200 K temperature range. results show that...

A method with which to calculate the Gilbert damping parameter from a real-space electronic structure is reported here. The anisotropy of respect magnetic moment direction and local chemical environment calculated for bulk surfaces ${\mathrm{Fe}}_{50}{\mathrm{Co}}_{50}$ alloys first-principles in formulation. size demonstrated be significant. Depending on details simulations, it reaches maximum-minimum ratio as high 200%. Several microscopic origins strongly enhanced have been examined,...

Structurally similar transition metal systems can exhibit very different magnetic properties. An instructive example is the widely studied Pd/Fe/Ir(111) multilayer, which shows a spin-spiral ground state, while Pd/Co/Ir(111) presents ferromagnetic (single-domain) state. Here, authors analyze origin of this difference combining $a\phantom{\rule{0}{0ex}}b$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$ and atomistic...

The oxygen octahedral rotations in ${\mathrm{Ca}}_{2}\mathrm{Mn}{\mathrm{O}}_{4}$, the first member of $\mathrm{Ca}\mathrm{O}{({\mathrm{CaMnO}}_{3})}_{n}$ Ruddlesden-Popper family, is probed through a set complementary techniques, including temperature-dependent neutron and x-ray diffraction, combined with local probe studies ab initio calculations. Here we demonstrate enhancement uniaxial negative thermal expansion coefficient from $\ensuremath{-}1.26\ifmmode\pm\else\textpm\fi{}0.25$ to...

Perturbed angular correlation spectroscopy combined with ab initio electronic structure calculations is used to unravel the structural phase transition path from low-temperature polar high-temperature in ${\mathrm{Ca}}_{3}{\mathrm{Ti}}_{2}{\mathrm{O}}_{7}$, a hybrid improper ferroelectric. The experimental procedure, conducted at ISOLDE, explores unique features of local probe environment approach by monitoring evolution electric field gradient tensor calcium sites. environments, observed...

<italic>Ab initio</italic> study on correlation of electric polarization and field gradient in hybrid improper ferroelectrics based Ruddlesden–Popper phases double perovskite structures.

A combined approach using first-principles calculations and spin dynamics simulations is applied to study $\mathrm{Ni}/{\mathrm{Ir}}_{n}/\mathrm{Pt}(111)$ ($n=0,1,2$) films. The lowest-energy states are predicted be spirals but with a minute (of the order of few $\ensuremath{\mu}\mathrm{eV}/\mathrm{atom}$) energy difference skyrmionic states. spontaneous low-temperature skyrmions, $\ensuremath{\sim}15$ nm $\ensuremath{\sim}35$ size, arise from large Dzyaloshinskii-Moriya (DM) Heisenberg...

Theoretical study of chemical substitution effects in the ferroelectric properties Cd-based Ruddlesden–Popper and double perovskite structures.

Magnetic properties of Mn linear nanochains on a bcc Fe(1 1 0) surface have been studied using the first-principles real space-linear muffin-tin orbital atomic sphere approximation (RS-LMTO-ASA) method. We considered up to nine atoms deposited 0). Our ab initio calculations reveal competition between antiferromagnetic Mn-Mn and Mn-Fe couplings, presenting behavior which is very different from nanowires Fe(0 0 1), as shown in previous publication. Due this non-negligible Dzyaloshinskii-Moriya...

We present a metaheuristic conditional neural-network-based method aimed at identifying physically interesting metastable states in potential energy surface of high rugosity. To demonstrate how this works, we identify and analyze spin textures with topological charge $Q$ ranging from 1 to $\ensuremath{-}13$ (where antiskyrmions have $Q&lt;0$) the Pd/Fe/Ir(111) system, which model using classical atomistic Hamiltonian based on parameters computed density functional theory. facilitate harvest...

Ab initio study on stability properties and phase diagrams of Ca- Cd-related hybrid improper ferroelectric materials with the Ruddlesden–Popper double perovskite structures.

Perturbed angular correlation spectroscopy combined with $ab-initio$ electronic structure calculations is used to unravel the structural phase transition path from low-temperature polar high-temperature in $Ca_3Ti_2O_7$, a hybrid improper ferroelectric. This procedure explores unique features of local probe environment approach by monitoring evolution electric field gradient tensor at calcium sites. The environments, observed above 1057 K, confirm $A2_1am$ symmetry an orthorhombic $Acaa$...

The Landau-Lifshitz-Gilbert (LLG) and Landau-Lifshitz (LL) equations play an essential role for describing the dynamics of magnetization in solids. While a quantum analog LL has been proposed [Phys. Rev. Lett. 110, 147201 (2013)], corresponding version LLG remains unknown. Here, we propose such equation that inherently conserves purity state. We examine dimer consisting two interacting spin-1/2 particles. Our analysis reveals that, case ferromagnetic coupling, evolution initially...

To develop new devices based on synthetic ferrimagnetic (S-FiM) heterostructures, understanding the material's physical properties is pivotal. Here, induced magnetic moment (IMM), exchange-coupling, and spin textures were investigated at room-temperature in Pt/Co/Gd multilayers using a multiscale approach. The magnitude direction of IMM interpreted experimentally theoretically framework both X-ray circular dichroism (XMCD) density functional theory (DFT). results demonstrate that transferred...

An optimal protocol for the current-induced switching of a perpendicularly magnetized nanoelement placed on surface topological insulator is presented. The time dependence both in-plane components current that induces magnetization reversal via Dirac spin-orbit torque with minimal Joule heating derived analytically as function required and material properties. It demonstrated particularly energy-efficient realized vanishing dampinglike torque. providing tradeoff between speed energy...

Magnetoelasticity plays a crucial role in numerous magnetic phenomena, including magnetocalorics, magnon excitation via acoustic waves, and ultrafast demagnetization/Einstein-de Haas effect. Despite long-standing discussion on anisotropy-mediated magnetoelastic interactions of relativistic origin, \textit{ab-initio} calculations, the exchange-mediated parameters within an atomistic framework have only recently begun to be investigated. As result, many their behaviors values for real...

The impact of the local chemical environment on Gilbert damping in binary alloy <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:msub><a:mi>Fe</a:mi><a:mrow><a:mn>100</a:mn><a:mo>−</a:mo><a:mi>x</a:mi></a:mrow></a:msub><a:msub><a:mi>Co</a:mi><a:mi>x</a:mi></a:msub></a:mrow></a:math> is investigated, using computations based density functional theory. By varying composition <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mi>x</b:mi></b:math> as well Fe-Co atom positions...

The Landau-Lifshitz-Gilbert (LLG) and Landau-Lifshitz (LL) equations play an essential role for describing the dynamics of magnetization in solids. While a quantum analog LL has been proposed [Phys. Rev. Lett. 110, 147201 (2013)PRLTAO0031-900710.1103/PhysRevLett.110.147201], corresponding version LLG remains unknown. Here, we propose such equation that inherently conserves purity state. We examine dimer consisting two interacting spin-1/2 particles. Our analysis reveals that, case...

The behavior of local magnetic moments and exchange coupling parameters FexCo1-x nanostructures (nanowires compact clusters) on the fcc Pt(1 1 1) surface is here investigated using first-principles real-space RS-LMTO-ASA method, in framework DFT. Different configurations trimers heptamers are considered, varying positions concentration Fe or Co atoms. We discuss influence dimensionality stoichiometry changes properties, specially orbital moments, which very important establishing a...

We present a metaheuristic conditional neural-network-based method aimed at identifying physically interesting metastable states in potential energy surface of high rugosity. To demonstrate how this works, we identify and analyze spin textures with topological charge $Q$ ranging from 1 to $-13$ (where antiskyrmions have $Q<0$) the Pd/Fe/Ir(111) system, which model using classical atomistic Hamiltonian based on parameters computed density functional theory. facilitate harvest relevant...