相关论文: Finite-size versus Surface effects in nanoparticle…
Magnetic nanoparticles are important building blocks for future technologies ranging from nano-medicine to spintronics. Many related applications require nanoparticles with tailored magnetic properties. However, despite significant efforts…
The performance of magnetic nanoparticles is intimately entwined with their structure, mean size and magnetic anisotropy. Besides, ensembles offer a unique way of engineering the magnetic response by modifying the strength of the dipolar…
The possible manifestations of magnetic screening effects were theoretically investigated for a particle with a ferromagnetic single-domain core and a magnetically soft shell. The exact solution of the Laplace equation gave analytical…
Nanographite systems, where graphene sheets of the orders of the nanometer size are stacked, show novel magnetic properties, such as, spin-glass like behaviors and the change of ESR line widths in the course of gas adsorptions. We…
The generalized Fisher super-exchange antiferromagnetic model with uniaxial crystal-field anisotropy is exactly investigated using an extended mapping technique. An exact relation between partition function of the studied system and that…
Equations of the magnetization dynamics are derived for an arbitrary curved 2D surface. General static solutions are obtained in the limit of a strong anisotropy of both signs (easy-surface and easy-normal cases). It is shown that the…
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…
By means of the molecular dynamics simulation on gradual cooling processes, we investigate magnetic properties of classical spin systems only with the magnetic dipole-dipole interaction, which we call dipolar systems. Focusing on their…
We study the relaxation characteristics in the two-dimensional ($l^{}_x \times l^{}_y$) array of magnetic nanoparticles (MNPs) as a function of aspect ratio $A^{}_r=l^{}_y/l^{}_x$, dipolar interaction strength $h^{}_d$ and anisotropy axis…
The Nd permanent magnet (Nd$_{2}$Fe$_{14}$B) is an indispensable material used in modern energy conversion devices. The realization of high coercivity at finite temperatures is a burning issue. One of the important ingredients for…
Assemblies of magnetic nanoparticles exhibit interesting physical properties arising from the competition of intraparticle dynamics and interparticle interactions. In ordered arrays of magnetic nanoparticles magnetostatic interparticle…
Binary random compacts with different proportions of small (volume V) and large (volume 2V) bare maghemite nanoparticles (NPs) are used to investigate the effect of controllably broadening the particle size distribution on the magnetic…
We model the stabilization of clusters and lattices of cuboidal particles with long-ranged magnetic dipolar and short-ranged surface interactions. Two realistic systems were considered: one with magnetization orientated in the [001]…
How does magnetism behave when the physical dimension is reduced to the size of nanostructures? The multiplicity of magnetic states in these systems can be very rich, in that their properties depend on the atomic species, the cluster size,…
In several experiments the magnitude of the contribution of magnetic impurities to the Kondo resistivity shows size dependence in mesoscopic samples. It was suggested ten years ago that magnetic surface anisotropy can be responsible for the…
We study the slow phase of thermally activated magnetic relaxation in finite two-dimensional ensembles of dipolar interacting ferromagnetic nanoparticles whose easy axes of magnetization are perpendicular to the distribution plane. We…
We investigate the consequence of the dimension reduction on the magnetic anisotropy of FePt and CoPt nanoparticles. Using an extension of the magnetic anisotropy model of N\'eel, we show that, due to a statistical finite size effect,…
We study the effective anisotropy induced in thin nanomagnets by the nonlocal demagnetization field (dipole-dipole interaction). Assuming a magnetization independent of the thickness coordinate, we reduce the energy to an inhomogeneneous…
We present a model to study effects from an external magnetic field, chemical potential, and finite size, on the phase structure of a massive four- and six-fermion interacting system. These effects are introduced by a method of…
We study the effect of a magnetic field on the thermal relaxation of non-interacting small monodomain particle systems particles with a distribution of anisotropy constants and random easy-axes directions. Numerical calculations of the…