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Related papers: Magnetic nanoparticles as many-spin systems

200 papers

Magnetic nanostructures are often considered as highly functional materials because they exhibit unusual magnetic properties under different external conditions. We study the effect of surface pinning on the core-shell magnetic…

Mesoscale and Nanoscale Physics · Physics 2020-02-19 Aditi Sahoo , Dipten Bhattacharya , P. K. Mohanty

We investigate the spatial distribution of spin orientation in magnetic nanoparticles consisting of hard and soft magnetic layers. The nanoparticles are synthesized in a core / shell spherical morphology where the magnetically hard, high…

Mesoscale and Nanoscale Physics · Physics 2021-05-26 C. Kons , K. L. Krycka , J. Robles , Nikolaos Ntallis , Manuel Pereiro , Manh-Huong Phan , Hariharan Srikanth , J. A. Borchers , D. A. Arena

Despite extensive researches on manganites owing to widespread use in modern electronics, this class of metal oxides does not cease to surprise with its unique properties and new phenomena. Here we have studied structural and magnetic…

Conventional and spin-related thermoelectric effects in electronic transport through a nanoscopic system exhibiting magnetic anisotropy $-$with both uniaxial and transverse components$-$ are studied theoretically in the linear response…

Mesoscale and Nanoscale Physics · Physics 2015-11-13 Maciej Misiorny , Józef Barnaś

We theoretically investigate the magnetic properties and nonequilibrium dynamics of two interacting ultracold polar and paramagnetic molecules in a one-dimensional harmonic trap in external electric and magnetic fields. The molecules…

Atomic Physics · Physics 2023-03-21 Anna Dawid , Michał Tomza

We investigate the signature of magnetic surface anisotropy in nanoparticles in their spin-flip neutron scattering cross section. Taking into account the isotropic exchange interaction, an external magnetic field, a uniaxial or cubic…

Materials Science · Physics 2023-11-13 Michael P. Adams , Evelyn Pratami Sinaga , Hamid Kachkachi , Andreas Michels

We study the interplay between the effects of surface anisotropy and dipolar interactions in monodisperse assemblies of nanomagnets with oriented anisotropy. We derive asymptotic formulas for the assembly magnetization taking account of…

Mesoscale and Nanoscale Physics · Physics 2013-09-27 Z. Sabsabi , F. Vernay , O. Iglesias , H. Kachkachi

Superparamagnetic nanoparticles containing hundreds and thousands of coupled electron spins are on the boundary between classical and quantum behavior, and demonstrate features which are typical for paramagnetic spins and absent in…

Mesoscale and Nanoscale Physics · Physics 2016-05-05 Natalia Noginova , Brittany Bates , Vadim A. Atsarkin

Direction-dependent anisotropic exchange is a common feature of magnetic systems with strong spin-orbit coupling. Here we study the effect of such exchange upon macroscopic magnetic anisotropy for a face-centered-cubic model. By several…

Strongly Correlated Electrons · Physics 2015-07-29 Hiroaki Ishizuka , Leon Balents

We consider a single spherical nanomagnet and investigate the spatial magnetization profile $\mathbf{m}\left(\mathbf{r}\right)$ in the continuum approach, using the Green's function formalism. The energy of the (many-spin) nanomagnet…

Mesoscale and Nanoscale Physics · Physics 2023-09-13 M. P. Adams , A. Michels , H. Kachkachi

The performance characteristics of magnetic nanoparticles towards application, e.g. in medicine, imaging, or as sensors, is directly determined by their magnetization relaxation and total magnetic moment. In the commonly assumed picture,…

We investigate the interaction between spherical magnetic nanoparticles which present either a single domain or a vortex structure. First the magnetic structure of a uniaxial soft sphere is revisited, and then the interaction energy is…

Materials Science · Physics 2009-03-31 V. Russier

We study the effect of free boundaries in finite magnetic systems of cubic shape on the field and temperature dependence of the magnetization within the isotropic model of D-component spin vectors in the limit D \to \infty. This model is…

Statistical Mechanics · Physics 2009-10-31 H. Kachkachi , D. A. Garanin

We investigate the effect of coupling (intensity and nature), applied field, and anisotropy on the spin dynamics of a multi-layer system composed of a hard magnetic slab coupled to a soft magnetic slab through a nonmagnetic spacer. The soft…

Materials Science · Physics 2015-06-12 Andres Felipe Franco , Hamid Kachkachi

We consider a simple model of maghemite nanoparticles and study their magnetic properties using Monte Carlo methods. The particles have a spherical geometry with diameters ranging from 3 nm to 8 nm. The interior of the particles consists of…

Statistical Mechanics · Physics 2015-03-13 K. Adebayo , B. W. Southern

Some of the synthesis methods and physical properties of iron-oxide based magnetic nanoparticles such as Fe3-xO4 and CoxFe3-xO4 are reviewed because of their interest in health, environmental applications, and ultra-high-density magnetic…

We investigate the effect of anisotropy and weak dipolar interactions on the magnetization of an assembly of nanoparticles with distributed magnetic moments, i.e., assembly of magnetic nanoparticles in the one-spin approximation, with…

Statistical Mechanics · Physics 2009-11-11 H. Kachkachi , M. Azeggagh

In this paper we review some results of our works on the magnetization processes in: i) Isolated nanomagnets, both in the one-spin approximation and as many-spin systems. Here, we focus on the intrinsic properties, e.g., those induced by…

Statistical Mechanics · Physics 2007-05-23 H. Kachkachi

We investigate the thermally activated magnetization switching of small ferromagnetic particles driven by an external magnetic field. For low uniaxial anisotropy the spins can be expected to rotate coherently, while for sufficient large…

Statistical Mechanics · Physics 2009-10-31 D. Hinzke , U. Nowak

The mechanisms of thermally activated magnetization switching in small ferromagnetic particles driven by an external magnetic field are investigated. For low uniaxial anisotropy the spins rotate coherently while for sufficiently large…

Statistical Mechanics · Physics 2009-10-31 U. Nowak , D. Hinzke