Related papers: Dipolar interactions and thermal stability of two-…
Each single domain nano-magnet acts as a magnetic dipole in addition it oscillates its magnetization about the easy axis and rotates coherently depending upon temperature and anisotropy. In an ensemble of nano-magnets, the relaxation time…
We study from tempered Monte Carlo simulations the magnetic phase diagram of a textured dipolar Ising model on a face centered cubic lattice. The Ising coupling of the model follow the dipole-dipole interaction. The Ising axes are…
Nonmagnetic spheres confined in a ferrofluid layer (magnetic holes) present dipolar interactions when an external magnetic field is exerted. The interaction potential of a microsphere pair is derived analytically, with a precise care for…
We study the effect of dipolar interactions on a magnetic striped monolayer with a microscopic unit cell of square symmetry, and of size $(N_x\times N_y)$ spins. Even if the aspect ratio $r=N_x/N_y$ is very large, an in-plane shape…
Using a nonequilibrium Monte Carlo method suitable to nanomagnetism, we investigate representative systems of interacting sub-10nm grained nanomagnets with large uniaxial anisotropy. Various magnetization memory and aging effects are found…
The interaction between spherical magnetic nanoparticles is investigated from micromagnetic simulations and ananlysed in terms of the leading dipolar interaction energy between magnetic dipoles. We focus mainly on the case where the…
The dipole-dipole interaction influences nanoscopic matter by fixing the patterns of permanent, displacive, and induced dipole moments, subject to constraints of molecular size and other short range interactions. Prediction of these…
We present the results of Monte Carlo simulations of the magnetic properties of a model for a single nanoparticle consisting in a ferromagnetic core surrounded by an antiferromagnetic shell. The simulations of hysteresis loops after cooling…
The classical, square lattice, uniaxially anisotropic Heisenberg antiferromagnet in a magnetic field parallel to the easy axis is studied using Monte Carlo techniques. The model displays a long-range ordered antiferromagnetic, an…
There are strong evidences that the melting in two dimensions depends crucially on the form and range of the interaction potentials between particles. We study with Monte Carlo simulations the phase diagram and the melting of a monolayer of…
It is shown that there is bi-stability in a two dimensional system consisting of non interacting magnetic nanoparticles with equal uniaxial anisotropies. It is also shown that bi-stability still remains in three dimensions. The only…
By tempered Monte Carlo simulations, we study site-diluted Ising systems of magnetic dipoles. All dipoles are randomly placed on a fraction x of all L^3 sites of a simple cubic lattice, and point along a given crystalline axis. For x_c<…
The dipolar interaction is known to substantially affect the properties of magnetic nanoparticles. This is particularly important when the particles are kept in a fluid suspension or packed inside nano-carriers. In addition to its usual…
We perform Monte Carlo simulations in a random anisotropy magnet at a intermediate exchange to anisotropy ratio. We focus on the out of equilibrium relaxation after a sudden quenching in the low temperature phase, well below the freezing…
In a two-dimensional arrangement of closely spaced elliptical nanomagnets with in-plane magnetic anisotropy, whose major axes are aligned along columns and minor axes along rows, dipole coupling will make the magnetic ordering…
We have developed a tunable colloidal system and a corresponding simulation model for studying the phase behavior of particles assembling under the influence of long-range magnetic interactions. A monolayer of paramagnetic particles is…
In a recent letter Alonso et al. (Phys. Rev. Lett. 87, 097205 (2001)) present Monte Carlo simulations for interacting dipoles. Short-time relaxation was caused by a simple noise field, acting uniformly over an "energy window" of small width…
We study a two-dimensional fluid of dipolar hard disks by Monte Carlo simulations in a square with periodic boundary conditions and on the surface of a sphere. The theory of the dielectric constant and the asymptotic behaviour of the…
The study of the response of magnetic nanoparticles (MNP) assemblies to an external alternating magnetic field is of great interest for applications such as hyperthermia. The key quantity here is the complex susceptibility and its behavior…
We revisit the theory of magnetoresistance for a system of nanoscopic magnetic granules in metallic matrix. Using a simple model for the spin dependent perturbation potential of the granules, we solve Boltzmann equation for the spin…