相关论文: Anisotropy in Ferromagnetic Nanoparticles: Level-t…
We calculate the anisotropy energy of a single-domain ferromagnetic particle in which the only source of anisotropy is the presence of non-magnetic impurities. We find that such anisotropy takes the form of combined easy-axis and easy-plane…
The conductance of a ferromagnetic particle depends on the relative orientation of the magnetization with respect to the direction of current flow. This phenomenon is known as "anisotropic magnetoresistance". Quantum interference leads to…
The thermal activation of magnetization reversal in magnetic nanoparticles is controlled by the anisotropy-energy barrier. Using perturbation theory, exact diagonalization and stability analysis of the ferromagnetic spin-s Heisenberg model…
In the presence of spin-orbit scattering, the splitting of an energy level in a generic small metal grain due to the Zeeman coupling to a magnetic field B depends on the direction of B, as a result of mesoscopic fluctuations. The anisotropy…
We use a microscopic Slater-Koster tight-binding model with short-range exchange and atomic spin-orbit interactions that realistically captures generic features of ferromagnetic metal nanoparticles to address the mesoscopic physics of…
Micromagnetic small-angle neutron scattering theory is well established for analyzing spin-misalignment scattering data of bulk ferromagnets. Here, this theory is extended to allow for a global uniaxial magnetic anisotropy (texture) of the…
It is shown that the observed anisotropy of magnetization at high magnetic fields in RbMnBr3 , a quasi-one-dimensional antiferromagnet on a distorted stacked triangular lattice, is due to quantum and thermal fluctuations. These fluctuations…
We evaluate the distribution function of mesoscopic fluctuations of orbital magnetic response in finite-size level-quantized metal particles and Aharonov-Bohm rings for temperatures smaller than the mean level spacing. We find a broad…
Direction-dependent anisotropic exchange is a common feature of magnetic systems with strong spin-orbit coupling. Here we study the effect of such exchange upon macroscopic magnetic anisotropy for a face-centered-cubic model. By several…
We report the precessional rotation of magnetically isotropic ferromagnetic nanoparticles in a viscous liquid that are subjected to a rotating magnetic field. In contrast to magnetically anisotropic nanoparticles, the rotation of which…
The influence of uniaxial anisotropy and the dipole interaction on the direction of the magnetization of ultra-thin ferromagnetic films in the ground-state is studied. The ground-state energy can be expressed in terms of anisotropy…
We have studied the magnetic behavior of dextran-coated magnetite (Fe$_3$O$_4$) nanoparticles with median particle size $\left<d\right>=8$ $nm$. Magnetization curves and in-field M\"ossbauer spectroscopy measurements showed that the…
We investigate the spin-magnetism of mesoscopic metallic grains. In the average response of an ensemble of grains there are corrections to macroscopic behaviour due to both spectral fluctuations and electron-electron interactions. These…
We have constructed an analytic formula to treat the perpendicular magnetic anisotropy energy in ferromagnetic metals with low symmetry, such as C4V and C3V. We find that the anisotropy energy is proportional to a part of the expectation…
The local magnetic anisotropy of a typical crystalline compound is usually attributed to the combined effect of crystal electric fields and spin-orbit coupling. We show that this simple local picture is transformed in heavy-fermion…
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…
We address the electronically induced anisotropy field acting on a spin moment comprised in a vibrating magnetic molecule located in the junction between ferromagnetic metals. Under weak coupling between the electrons and molecular…
We show that the magnetic anisotropy energy of antiferromagnetic ferrihydrite depends on the square root of the nanoparticles volume, using a method based on the analysis of statistical distributions. The size distribution was obtained by…
We investigate the thermal activated magnetisation reversal in a single ferromagnetic nanoparticle with uniaxial anisotropy using Monte Carlo simulations. The aim of this work is to reproduce the reversal magnetisation by uniform rotation…
We present an experimental study of macroscopic and microscopic magnetic anisotropy of a spin tetramer system \cso using torque magnetometry and ESR spectroscopy. Large rotation of macroscopic magnetic axes with temperature observed from…