相关论文: Surface effects in nanoparticles: application to m…
A potassium alumina borosilicate glass with the composition 13K2O*13Al2O3*16B2O3*43SiO2*15Fe2O3-x was melted using Fe2O3 as raw material. The melt was dumped from a Pt-crucible with a downpipe in water which resulted in the formation of…
We explore possible ways to manipulate the intrinsic edge magnetism in hexagonal graphene nanoflake with zigzag edges, using density functional theory supplemented with on-site Coulomb interaction. The effect of carrier doping, chemical…
The magnetization curves of densely packed single domain magnetic nanoparticles (MNP) are investigated by Monte Carlo simulations in the framework of an effective one spin model. The particles whose size polydispersity is taken into account…
The mechanisms of thermally activated magnetization switching in small ferromagnetic particles driven by an external magnetic field are investigated. For low uniaxial anisotropy the spins rotate coherently while for sufficiently large…
Magnetic materials for specific applications require an accurate control and complete comprehension of their magnetic properties. In particular, nanoparticles embedded in a polycrystalline matrix emerge as good candidates for applications…
We report on the effect of organic acid capping on the behavior of magnetite nanoparticles. The nanoparticles of magnetite were obtained using microwave activated process, and the magnetic properties as well as the electron magnetic…
We focus on an in-depth study of the forced dynamics of a ferromagnetic single-domain uniaxial nanoparticle placed in a viscous fluid and driven by an external rotating magnetic field. The process of conversion of magnetic and mechanical…
We have developed a simple precipitation route to synthesize magnetite (Fe3O4) nano-particles with controlled size without any requirement of calcination step at high temperatures. The study of these nano-particles indicates an enhancement…
The surface magnetization of Fe$_3$GeTe$_2$ was examined by low-energy electron microscopy (LEEM) using an off-normal incidence electron beam. We found that the 180$^o$ domain walls are of Bloch type. Temperature-dependent LEEM measurements…
In transition metal oxides, quantum confinement arising from a large surface to volume ratio often gives rise to novel physico-chemical properties at nanoscale. Their size dependent properties have potential applications in diverse areas,…
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…
Vortex core reversal in magnetic particle is essentially influenced by a surface anisotropy. Under the action of a perpendicular static magnetic field the vortex core undergoes a shape deformationof pillow- or barrel-shaped type, depending…
Spinel Fe3O4 nanoparticles have been produced through ball milling in methyl-alcohol (CH3OH), aiming to obtain samples with similar average particle sizes <d> and different interparticle interactions. Three samples having Fe3O4/CH3(OH) mass…
The linear and cubic dynamic susceptibilities of solid dispersions of nano-sized maghemite particles have been measured for three samples with a volume concentration of magnetic particles ranging from 0.3 % to 17 %, in order to study the…
Co-based nanostructures ranging from core-shell to hollow nanoparticles were produced by varying the reaction time and the chemical environment during the thermal decomposition of Co2(CO)8. Both structural characterization and kinetic model…
The results of large-scale simulations investigating the dynamics of magnetization reversal in arrays of single-domain nanomagnets after a rapid reversal of the applied field at nonzero temperature are presented. The numerical micromagnetic…
In this work, we study the effect of dipole-dipole interparticle interactions on the static thermodynamic and magnetic properties of an ensemble of immobilized monodisperse superparamagnetic nanoparticles. We assume that magnetic…
The dynamic magnetic properties of Ni nanoparticles diluted in an amorphous SiO2 matrix prepared from a modified sol-gel method have been studied by the frequency f dependence of the ac magnetic susceptibility \c{hi}(T). For samples with…
Most previous investigations have shown that the surface of a ferromagnetic material may have antiferromagnetic tendencies. However, experimentally the opposite effect has been recently observed: ferromagnetism appears in some nano-sized…
In this report, the magnetic behaviour of $NiCr_{2}O_{4}$ bulk and nanoparticle samples under different applied magnetic field has been investigated extensively. Nanoparticles of $NiCr_{2}O_{4}$ were obtained by mechanical milling of…