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Related papers: Imaging magnetic vortex configurations in ferromag…

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Vortex rings are remarkably stable structures occurring in numerous systems: for example in turbulent gases, where they are at the origin of weather phenomena [1]; in fluids with implications for biology [2]; in electromagnetic discharges…

Nanodots with magnetic vortices have many potential applications, such as magnetic memories (VRAMs) and spin transfer nano-oscillators (STNOs). Adding a perpendicular anisotropy term to the magnetic energy of the nanodot it becomes possible…

Mesoscale and Nanoscale Physics · Physics 2015-05-28 E. R. P. Novais , P. Landeros , A. G. S. Barbosa , M. D. Martins , F. Garcia , A. P. Guimarães

We show that the curvature of nanomagnets can be used to induce chiral textures in the magnetization field. Among the phenomena related to the interplay between geometry and magnetic behavior at nanomagnets, an effective curvature-induced…

Mesoscale and Nanoscale Physics · Physics 2017-04-05 Smiljan Vojkovic , Vagson L. Carvalho-Santos , Jakson M. Fonseca , Alvaro S. Nunez

In this work, and by means of micromagnetic simulations, we study the magnetic properties of toroidal nanomagnets. The magnetization ground state for different values of the aspect ratio between the toroidal and polar radii of the nanotorus…

Mesoscale and Nanoscale Physics · Physics 2016-08-03 Smiljan Vojkovic , Álvaro S. Núñez , Dora Altbir , Vagson L. Carvalho-Santos

We demonstrate a novel method allowing the study of the magnetic state dynamics of a single nanoparticle by means of electron transport measurements. Elliptical 550 nm x 240 nm permalloy nanoparticles are wired with non-magnetic leads for…

Materials Science · Physics 2010-07-07 Dmitry Ruzmetov , Venkat Chandrasekhar

Nanoscale structural and electronic heterogeneities are prevalent in condensed matter physics. Investigating these heterogeneities in three dimensions (3D) has become an important task for understanding their material properties. To provide…

The mechanism of the interplay between superconductivity and magnetism is one of the intriguing and challenging problems in physics. Theory has predicted that the ferromagnetic order can coexist with the superconducting order in the form of…

Superconductivity · Physics 2020-10-05 Nanami Teramachi , Yusuke Seto , Takahiro Sakurai , Hithoshi Ohta , Takashi Uchino

The switching process of the vortex core in a Permalloy nanodisk affected by a rotating magnetic field is studied theoretically. A detailed description of magnetization dynamics is obtained by micromagnetic simulations.

Strongly Correlated Electrons · Physics 2007-08-26 Volodymyr P. Kravchuk , Denis D. Sheka , Yuri Gaididei , Franz G. Mertens

The recording of planetary magnetic fields is often attributed to uniformly-magnetised nanoscopic iron oxides, called single-domain (SD). Yet, the main magnetic constituents of rocks are more complex, non-uniformly magnetised grains in…

A model for describing structural pointlike defects in nanoscaled ferromagnetic materials is presented. Its details are explicitly developed whenever interacting with a vortex-like state comprised in a thin nanodisk. Among others, our model…

Mesoscale and Nanoscale Physics · Physics 2011-08-05 F. A. Apolonio , W. A. Moura-Melo , F. P. Crisafulli , A. R. Pereira , R. L. Silva

We investigate single CoFeB nanotubes with hexagonal cross-section using dynamic cantilever magnetometry (DCM). We develop both an analytical model based on the Stoner-Wohlfarth approximation and a broadly applicable numerical framework for…

Mesoscale and Nanoscale Physics · Physics 2016-02-09 B. Gross , D. P. Weber , D. Rüffer , A. Buchter , F. Heimbach , A. Fontcuberta i Morral , D. Grundler , M. Poggio

Ferrogels, i.e., hydrogels loaded with magnetic nanoparticles, have the ability to deform in external magnetic fields. The precise shape of deformation and the alignment of the gel in the field, however, depend on the interplay of several…

Soft Condensed Matter · Physics 2017-04-24 Rudolf Weeber , Christian Holm

Using analytical expressions for the magnetization textures of thin submicron-sized magnetic cylinders in vortex state, we derive closed-form algebraic expressions for the ensuing small-angle neutron scattering (SANS) cross sections.…

Mesoscale and Nanoscale Physics · Physics 2016-04-27 Konstantin L. Metlov , Andreas Michels

We present results of micromagnetic simulations of thin ferromagnetic nano hemispheroidal shells with sizes ranging from 1 to 50 nm (inside dimensions). Depending on the geometrical and magnetic parameters of the hemispheroidal shell, there…

Mesoscale and Nanoscale Physics · Physics 2017-08-23 Keren Schultz , Moty Schultz

We demonstrate how micromagnetic simulations can be employed in order to characterize and analyze the magnetic microstructure of nanocomposites. For the example of nanocrystalline Nd$-$Fe$-$B, which is a potential material for future…

Materials Science · Physics 2018-04-04 Sergey Erokhin , Dmitry Berkov , Masaaki Ito , Akira Kato , Masao Yano , Andreas Michels

Magnetic disks or dots of soft magnetic material of sub-micron dimensions may have as the lowest energy magnetic configuration a single-domain structure, with magnetization either perpendicular of parallel to the plane, or else may form…

Mesoscale and Nanoscale Physics · Physics 2009-10-01 E. R. P. Novais , A. P. Guimarães

We use a sensitive magneto-optical microscopy technique to image the magnetization response of micron-scale ferromagnetic disks to changes in applied magnetic field. This differential technique relies on a modulated applied magnetic field…

Mesoscale and Nanoscale Physics · Physics 2015-12-09 Robert Badea , Johnathon A. Frey , Jesse Berezovsky

The authors apply first-principles calculations to investigate the interplay between structural, electronic, and magnetic properties of nanostructures composed of narrow nanotubes filled with metallic nanowires. The focus is on the…

Mesoscale and Nanoscale Physics · Physics 2010-09-06 Eduardo M. Diniz , Ricardo W. Nunes , Hélio Chacham , Mário S. C. Mazzoni

The spin dynamics are calculated for a model system consisting of magnetically soft, layered nanomagnets, in which two ferromagnetic (F) cylindrical dots, each with a magnetic vortex ground state, are separated by a non-magnetic spacer (N).…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 K. Yu. Guslienko , K. S. Buchanan , S. D. Bader , V. Novosad

The magnetic configurations of bi-phase micro- and nanotubes consisting of a ferromagnetic internal tube, an intermediate non-magnetic spacer, and an external magnetic shell are investigated as a function of their geometry. Based on a…

Materials Science · Physics 2007-11-08 J. Escrig , D. Altbir , K. Nielsch