Related papers: Macrospin approximation and quantum effects in mod…
Numerical solutions of the Landau-Lifshitz-Gilbert micromagnetic model incorporating thermal fluctuations and dipole-dipole interactions (calculated by the Fast Multipole Method) are presented for systems composed of nanoscale iron pillars…
Thermodynamic perturbation theory is employed to derive analytical expressions for the equilibrium linear susceptibility and specific heat of lattices of anisotropic classical spins weakly coupled by the dipole-dipole interaction. The…
The temperature dependence of magnetic anisotropy in (113)A (Ga,Mn)As layers grown by molecular beam epitaxy is studied by means of superconducting quantum interference device (SQUID) magnetometry as well as by ferromagnetic resonance (FMR)…
We develop an approach to treat magnetic energy of a ferromagnet for arbitrary curved wires and shells on the assumption that the anisotropy contribution much exceeds the dipolar and other weak interactions. We show that the curvature…
We investigate the effect of anisotropy and weak dipolar interactions on the magnetization of an assembly of nanoparticles with distributed magnetic moments, i.e., assembly of magnetic nanoparticles in the one-spin approximation, with…
The periodic deviations of ferromagnetic and antiferromagnetic spins from corresponding uniform configurations are shown to be energetically favorable close to a compensated interface of ferromagnetic antiferromagnetic bilayer. The…
Magnetic nanoparticles with Neel surface anisotropy, different internal structures, surface arrangements and elongation are modelled as many-spin systems. The results suggest that the energy of many-spin nanoparticles cut from cubic…
Thermal equilibrium properties of nanoscale systems deviate from standard macroscopic predictions due to a non-negligible coupling to the environment. For anisotropic three-dimensional materials, we derive the mean force corrections to the…
The tunneling of a giant spin at excited levels is studied theoretically in mesoscopic magnets with a magnetic field at an arbitrary angle in the easy plane. Different structures of the tunneling barriers can be generated by the…
We argue that for some species of magnetic nanoparticles the macrospin can have a nonvanishing moment of inertia and then an orbital angular momentum. We represent such nanoparticles by two interacting rigid rotors one of which has a large…
We study the effect of quantum fluctuations on the multiphase point of the Heisenberg model with first- and second-neighbor competing interactions and strong uniaxial spin anisotropy $D$. By studying the structure of perturbation theory we…
We review models for the nucleation of magnetisation reversal, i.e. the formation of a region of reversed magnetisation in an initially magnetically saturated system. For small particles models for collective reversal, either uniform…
The origins of the anomalous temperature dependence of magnetocrystalline anisotropy in (Fe$_{1-x}$Co$_{x}$)$_{2}$B alloys are elucidated using first-principles calculations within the disordered local moment model. Excellent agreement with…
$Co$-doping of $Fe_{3}O_{4}$ magnetic nanoparticles is an effective way to tailor their magnetic properties. When considering the two extreme cases of the $Co_{x}Fe_{3-x}O_{4}$ series, i.e. the $x=0$ and $x=1$ values, one finds that the…
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…
The effect of thermal fluctuations on a thin film magnetoresistive element has been calculated. The technique involves adding to the basic spin dynamics a general form of interaction with a thermal bath. For a general anisotropic magnetic…
A quantum theory of magnetization dynamics of a nanomagnet as a sequence of scatterings of each electron spin with the macrospin state of the magnetization results in each encounter a probability distribution of the magnetization recoil…
Spin fluctuations are considered to be one of the candidates that drive a sign-reversed s^{\pm} superconducting state in the iron pnictides. In the magnetic scenario, whether the spin fluctuation spectrum exhibits certain unique fine…
Macroscopic quantum coherence and spin-phase interference are studied between excited levels in single-domain ferromagnetic particles in a magnetic field along the hard anisotropy axis. The system has the general structure of…
Spin is a fundamental property of any many-electron system. The ability of density functional theory to accurately predict the physical properties of a system, while varying its spin, is crucial for describing magnetic materials and…