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Related papers: Thermal activation in permanent magnets

200 papers

We predict the existence of a torque acting on an isotropic neutral nanosphere activated by a static magnetic field when the particle temperature differs from the surrounding vacuum. This phenomenon originates in time-reversal symmetry…

Mesoscale and Nanoscale Physics · Physics 2019-06-26 Deng Pan , Hongxing Xu , F. Javier García de Abajo

In this work, we expose the role of environment, confinement and external magnetic field ($B$) in determining the low temperature thermodynamic behaviour in the context of cyclotron motion of a charged oscillator with anomalous dissipative…

Statistical Mechanics · Physics 2015-06-19 Asam Rajesh , Malay Bandyopadhyay

Ensuring a permanent increase of magnetic storage densities is one of the main challenges in magnetic recording. Conventional approaches based on single phase grains are not suitable to achieve this goal, because their grain volume is…

Computational Physics · Physics 2015-06-23 Christoph Vogler , Florian Bruckner , Dieter Suess , Christoph Dellago

We derive a simple system of equations to describe the magnetization relaxation of a molecular spin in weak interaction with a thermal bath for the whole temperature domain. Using this for the intermediate temperature domain where the…

Materials Science · Physics 2022-12-27 Le Tuan Anh Ho , Liviu Ungur , Liviu F. Chibotaru

We study temperature and finite-size effects on the spontaneous symmetry breaking/restoration for a scalar field model under the influence of an external magnetic field, at finite chemical potential. We use the 2PI formalism and consider…

High Energy Physics - Theory · Physics 2013-11-21 L. M. Abreu , C. A. Linhares , A. P. C. Malbouisson , J. M. C. Malbouisson

The high temperature limit of interacting spins is usually not associated with ordering or critical phenomena. Nevertheless, spontaneous fluctuations of a local spin polarization at equilibrium have nontrivial dynamics even in this limit.…

Statistical Mechanics · Physics 2023-07-03 V. N. Gorshkov , N. A. Sinitsyn , D. Mozyrsky

We study the influence of thermal fluctuations on the magnetic behavior of square mesoscopic superconductors. The strength of thermal fluctuations are parameterized using the Ginzburg number, which is small ($G_i \approx 10^{-10}$) in…

Superconductivity · Physics 2009-11-11 Alexander D. Hernandez , B. J. Baelus , Daniel Dominguez , F. M. Peeters

Applying a magnetic field to a solid changes its thermal-transport properties. Although such magneto-thermal-transport phenomena are usually small effects, giant magneto-thermal resistance has recently been observed in spintronic…

The stability of magnetic skyrmions has been investigated in the past, but mostly in the absence of thermal fluctuations. However, thermal spin fluctuations modify the magnetic properties (exchange stiffness, Dzyaloshinskii-Moriya…

Materials Science · Physics 2023-10-06 Ioannis Charalampidis , Joseph Barker

The thermodynamic uncertainty relation provides a universal lower bound on the product of entropy production and the fluctuations of any current. While proven for Markov dynamics on a discrete set of states and for overdamped Langevin…

Statistical Mechanics · Physics 2019-04-24 Hyun-Myung Chun , Lukas P. Fischer , Udo Seifert

The magnetization reversal process in thin-film ferromagnetic elements with surface anisotropy of various shapes and sizes is investigated by means of numerical simulation. The dependence of the perpendicular and in-plane hysteresis loops…

Mesoscale and Nanoscale Physics · Physics 2018-03-14 N. A. Usov , O. N. Serebryakova

We study finite temperature ($T$) properties of the continuum quantum field theory of systems with a ferromagnetic ground state. A scaling theory of the $T=0$ system is discussed carefully, and its consequences for crossovers between…

Condensed Matter · Physics 2009-10-28 N. Read , Subir Sachdev

The characteristic microstructure of Sm(Co,Fe,Cu,Zr)$_z$ alloys with SmCo$_5$ cell walls in Sm$_2$Co$_{17}$ cells, all intersected by Zr-rich platelets, makes them some of the best performing high-temperature permanent magnets. Plentiful…

The magnetotropic susceptibility is the thermodynamic coefficient associated with the rotational anisotropy of the free energy in an external magnetic field, and is closely related to the magnetic susceptibility. It emerges naturally in…

Strongly Correlated Electrons · Physics 2023-07-07 A. Shekhter , R. D. McDonald , B. J. Ramshaw , K. A. Modic

We present an ab initio quantum theory of the finite temperature magnetism of iron and nickel. A recently developed technique which combines dynamical mean-field theory with realistic electronic structure methods, successfully describes the…

Strongly Correlated Electrons · Physics 2007-05-23 A. I. Lichtenstein , M. I. Katsnelson , G. Kotliar

The field dependence of the thermal switching rate of a ferromagnetic material with uniaxial anisotropy was studied by solving the Fokker-Planck equation. We derived the analytical expression of the thermal switching rate using the mean…

Mesoscale and Nanoscale Physics · Physics 2012-05-04 Tomohiro Taniguchi , Hiroshi Imamura

We derive finite temperature expansions for relativistic fermion systems in the presence of background magnetic fields, and with nonzero chemical potential. We use the imaginary-time formalism for the finite temperature effects, the…

High Energy Physics - Theory · Physics 2009-10-30 Daniel Cangemi , Gerald Dunne

We study the magnetic orbital response of a system of N interacting electrons confined in a two-dimensional geometry and subjected to a perpendicular magnetic field in the finite temperature Hartree-Fock approximation. The electron-electron…

Mesoscale and Nanoscale Physics · Physics 2009-01-23 L. G. G. V. Dias da Silva , Caio H. Lewenkopf , Nelson Studart

We investigate the effect of hydrostatic pressure on temperature dependence of magnetization and also the influence of magnetic field on linear thermal expansion in polycrystalline Pr0.6Sr0.4MnO3, which is ferromagnetic at room temperature…

Materials Science · Physics 2018-08-15 Amit Chanda , R. Mahendiran

Ferrimagnetic GdCo5-xCux alloys exhibiting the effect of Gd- and 3d-sublattice magnetization compensation at defined temperatures were studied with respect to their use as thermo-reversible permanent magnets (PM). Coercive fields…