相关论文: Surface effects in nanoparticles: application to m…
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…
We study the finite-size and surface effects on the thermal and spatial behaviors of the magnetisation of a small magnetic particle. We consider two systems: 1) A box-shaped isotropic particle of simple cubic structure with either periodic…
We present the results of Monte Carlo simulations of a model of a single maghemite ferrimagnetic nanoparticle including radial surface anisotropy distinct from that in the core with the aim to clarify what is its role on the magnetization…
We present the results of Monte Carlo simulations of a model of a single maghemite ferrimagnetic nanoparticle with the aim to clarify the role played by the increased anisotropy at the surface and by the shape (spherical or elliptical) of…
We present the results of Monte Carlo simulations of the magnetic properties of individual spherical nanoparticles with the aim to explain the role played by surface anisotropy on their low temperature magnetization processes. Phase…
The influence of surface anisotropy on the magnetization processes of maghemite nanoparticles with ellipsoidal shape is studied by means of Monte Carlo simulations. Radial surface anisotropy is found to favor the formation of hedgehog-like…
In the present work, we investigate the magnetic properties of ferrimagnetic and noninteracting maghemite (g-Fe2O3) hollow nanoparticles obtained by the Kirkendall effect. From the experimental characterization of their magnetic behavior,…
We present a review of recent advances in the study of many-body effects in magnetic nanoparticles. Considering classical spins on a lattice coupled by the exchange interaction in the presence of the bulk and surface anisotropy, we…
A study of spherical maghemite nanoparticles on a two dimensional triangular array was carried out using a stochastic Landau-Lifshitz-Gilbert (sLLG) approach. The simulation method was first validated with a triangular array of simple…
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,…
Being inspired by a recent study [V. Dimitriadis et al. Phys. Rev. B \textbf{92}, 064420 (2015)], we study the finite temperature magnetic properties of the spherical nanoparticles with core-shell structure including quenched (i) surface…
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…
Magnetic nanoparticles (NP) of magnetite (Fe3O4) coated with oleic acid (OA) and dodecanoic acid (DA) were synthesized and investigated through Transmission Electron Microscopy (TEM),magnetization M, and ac magnetic susceptibility…
The role of particle size distribution inherently present in magnetic nanoparticles (NPs) is examined in considerable detail in relation to the measured magnetic properties of oleic acid-coated maghemite ({\gamma}-Fe$_2$O$_3$) NPs.…
The dielectric properties of MnFe$_2$O$_4$ and $\gamma$-Fe$_2$O$_3$ magnetic nanoparticles embedded in insulating matrices were investigated. The samples showed frequency dependent dielectric anomalies coincident with the magnetic blocking…
We study the low-temperature isothermal magnetic hysteresis of cubical and spherical nanoparticles with ferromagnetic (FM) core - antiferromagnetic (AF) shell morphology, in order to elucidate the sensitivity of the exchange bias effect to…
We use Monte Carlo simulation to study the vortex nucleation on magnetic nanodots at low temperature. In our simulations, we have considered a simple microscopic two-dimensional anisotropic Heisenberg model with term to describe the…
The dielectric properties of Fe$_{3}$O$_{4}$ magnetic nanoparticles with an insulating coating layer of SiO$_{2}$ were investigated. At high temperatures, the changes of the dielectric constant and loss induced by the magnetic field are…
We present the results of Monte Carlo simulations of a model of a $\gamma$-Fe$_2$ O$_3$ (maghemite) single particle of spherical shape. The magnetic Fe$^{3+}$ ions are represented by Ising spins on a spinel lattice that consists on two…
Magnetic nanoparticles of gamma-Fe2O3 coated by organic molecules and suspended in liquid and solid matrices, as well as a non-diluted magnetic fluid have been studied by electron magnetic resonance (EMR) at 77-380 K. Slightly asymmetric…