A Non-uniform Grid (NG) algorithm for rapidly computing magnetostatic field for micromagnetic simulations is described. The algorithm relies on spatial NG representation of the potential from the source boxes and local interpolation. Multi-level implementations of the algorithm result in a linear computational complexity with respect to the number of effective magnetic charges and observers. Th...

The interaction of two domain walls (DWs) at a cross-shaped vertex fabricated from two ferromagnetic nanowires has been experimentally investigated. Both magnetostatically repulsive and attractive interactions have been probed. It is found that in the repulsive case, a passing DW may directly induce the depinning of another that is already pinned at a vertex. This effect can be qualitatively de...

Using multidimensional particle-in-cell simulations, we show that the magnetic undulator-type field of the plasma magnetostatic mode is indeed produced by the interaction of a laser pulse with a relativistic ionization front, as predicted by linear theory for a cold plasma. When the front with this magnetostatic mode is followed by a relativistic electron beam, the interaction of the beam with ...

[1] Magnetostatic interactions have been investigated in an intergrown material consisting of 200-nm magnetite blocks separated by 30-nm-wide ulvöspinel lamellae. First-order reversal curve (FORC) measurements provide a direct measure of the interaction fields, giving a value for the full width at half maximum (FWHM) of 30 mT (at Hc = 20 mT). Hysteresis parameters are Mrs/Ms = 0.22, Hcr/Hc = 1....

In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: a r t i c l e i n f o a b s t r a c t Keywords: First-order reversal curve Nanocomposite magnets Magnetostatic and intergran...

To know the properties of a particle or a wave, one should measure how its energy changes with its momentum. The relation between them is called the dispersion relation, which encodes essential information of the kinetics. In a magnet, the wave motion of atomic spins serves as an elementary excitation, called a spin wave, and behaves like a fictitious particle. Although the dispersion relation ...

Efficient implementations of non-uniform grid method (NGM) for fast computation of magnetostatic field on general purpose Graphics Processing Units (GPUs) are introduced. The NGM reduces the computational complexity of the magnetostatic field evaluation from 2 ( ) O N to ( ) O N . It is shown that the massive parallelization of GPUs leads to significant speed-up of the NGM field evaluation. Wit...

[1] Ferromagnetic resonance spectroscopy (FMR) can be used to measure the effective magnetic field within a sample, including the contributions of both magnetic anisotropy and magnetostatic interactions. One particular use is in the detection of magnetite produced by magnetotactic bacteria. These bacteria produce single-domain particles with narrow size and shape distributions that are often el...

The behavior of grain-growth chemical remanent magnetizations (gCRM) are investigated for different coercivity and magnetostatic-interaction-field distributions acquisition conditions using a thermally activated Preisach model assemblages interacting single-domain grains. A new growth-rate dependent equation was derived, from which it found that gCRM intensity is over 10% more sensitive to grow...

We evaluate the energy barrier distributions of coupled Co particles as a function of their concentration, which changes the strength of magnetostatic interactions, in a multidimensional space to take into account possible collective reversal. The distributions are evaluated at the remanence, demagnetized state and coercivity for Co particles with 2D random anisotropy easy axes orientations and...