Search results for " susceptibility"
showing 10 items of 827 documents
Local control of domain wall dynamics in ferromagnetic rings
2015
Ferromagnetic nanorings are of great interest due to prospective applications in memory and logic devices based on domain wall (DW) motion.1-3A key-prerequisite for their realization is a reproducible domain wall spin structure with a well-controllable wall velocity. We have found that DW propagation in magnetic ring is characterized by non-constant vortex DW velocity even below Walker breakdown4 (as opposed to straight wires). Several studies have been devoted to the optimization of ring reversal on a global scale using out-of plane field5 or flux charges emanating from neighboring rings if placed in close proximity6. However, these methods involve DW pinning and vortex nucleation processe…
Dynamic domain wall chirality rectification by rotating magnetic fields
2015
We report on the observation of magnetic vortex domain wall chirality reversal in ferromagnetic rings that is controlled by the sense of rotation of a magnetic field. We use time-resolved X-ray microscopy to dynamically image the chirality-switching process and perform micromagnetic simulations to deduce the switching details from time-resolved snapshots. We find experimentally that the switching occurs within less than 4 ns and is observed in all samples with ring widths ranging from 0.5 μm to 2 μm, ring diameters between 2 μm and 5 μm, and a thickness of 30 nm, where a vortex domain wall is present in the magnetic onion state of the ring. From the magnetic contrast in the time-resolved im…
Highly Correlated Fermi Liquid in Heavy-Fermion Metals: Magnetic Properties
2014
In this chapter we show how the FCQPT theory works, when describing the behavior of HF metals under the application of magnetic field. We show that a large body of experimental data regarding the thermodynamic, transport and relaxation properties collected in measurements on HF metals can be well explained. It is demonstrated that the experimental data exhibit the scaling behavior.
Pressure-induced electron transfer in ferrimagnetic Prussian blue analogs
2003
M\"ossbauer and magnetic susceptibility measurements were performed under pressure on three Prussian blue analogs, ${\mathrm{K}}_{0.1}{\mathrm{Co}}_{4}[{\mathrm{Fe}(\mathrm{CN})}_{6}{]}_{2.7}\ensuremath{\cdot}18{\mathrm{H}}_{2}\mathrm{O},$ ${\mathrm{K}}_{0.28}{\mathrm{Co}}_{4}[{\mathrm{Fe}(\mathrm{CN})}_{6}{]}_{2.76}\ensuremath{\cdot}18{\mathrm{H}}_{2}\mathrm{O},$ and ${\mathrm{Cs}}_{0.7}{\mathrm{Co}}_{4}[{\mathrm{Fe}(\mathrm{CN})}_{6}{]}_{2.9}\ensuremath{\cdot}16{\mathrm{H}}_{2}\mathrm{O}.$ A pressure-induced electron transfer ${\mathrm{Co}}^{2+}(S=\frac{3}{2})\ensuremath{-}{\mathrm{Fe}}^{3+}(S=\frac{1}{2})\ensuremath{\rightarrow}{\mathrm{Co}}^{3+}(S=0)\ensuremath{-}{\mathrm{Fe}}^{2+}(S=0)…
Singlet-groundstate magnetism in TbP
1979
Elastic neutron scattering and magnetic susceptibility data are reported for temperatures around the Neel-point,TN=7.3 K, and for zero magnetic field. AboveTN, the temperature dependence of the magnetic central peak intensity can adequately be described within the RPA assuming isotropic exchange between nearest and next-nearest neighbours as the only parameters. This two-parameter model is quantitatively confirmed by the susceptibility data. AtTN, magnetic Bragg-intensities arise almost discontinuously (reaching 70% of the saturation within 0.1 K) accompanied by thermal hysteresis. For all temperatures belowTN the sublattice magnetic moment is explained by solutions of meanfield equations, …
Monte Carlo study of surface phase transitions in the three-dimensional Ising model.
1990
We present the results of extensive Monte Carlo simulations of phase transitions and critical behavior at the surface of a simple cubic Ising model. Profiles of the magnetization and internal energy are determined as a function of the distance from the surface, and we extract surface and bulk properties as a function of temperature and surface coupling ${\mathit{J}}_{\mathit{s}}$. The surface-bulk multicritical point is located with improved precision, ${\mathit{J}}_{\mathit{s}}$/J=1.52\ifmmode\pm\else\textpm\fi{}0.02, and crossover behavior is studied. New estimates for critical exponents are extracted, ${\ensuremath{\gamma}}_{1}$=0.78\ifmmode\pm\else\textpm\fi{}0.06, ${\ensuremath{\gamma}…
Laser even harmonics generation by a plasma embedded in a static electric field
2004
Even order harmonics generation of the laser radiation due to electron-ion collisions in a plasma embedded in a constant electric field is investigated theoretically. Even harmonics are generated because the presence of a static electric field removes the invariance of the electron distribution function under the symmetry operation of velocity direction inversion. Efficiency generation dependencies are investigatedvsdifferent significant parameters as: harmonics number; the ratio of the electron quiver velocity to the thermal velocity; the orientation of the constant electric field with respect to the laser radiation electric field and its wavevector. It is shown that in the general case th…
Molecular analog of multiferroics: Electric and magnetic field effects in many-electron mixed-valence dimers
2012
We show here that mixed-valence (MV) magnetic molecules with a significant electron delocalization are extremely sensitive to an external electric field. In particular, we focus on the symmetric many-electron MV binuclear complexes that are on the borderline between Robin and Day classes II and III. In these molecules, the double-exchange, which has been shown to lead to the ferromagnetic ground spin state, competes with the electric field, which tends to localize the spin, thus creating an electric dipole and stabilizing the spin states with lower multiplicities. This provides an efficient and easy way to control the ground spin state of the molecule through the double-exchange mechanism. …
A scheme for entanglement extraction from a solid
2006
Some thermodynamical properties of solids, such as heat capacity and magnetic susceptibility, have recently been shown to be linked to the amount of entanglement in a solid. However this entanglement may appear a mere mathematical artifact of the typical symmetrization procedure of many-body wave function in solid state physics. Here we show that this entanglement is physical demonstrating the principles of its extraction from a typical solid state system by scattering two particles off the system. Moreover we show how to simulate this process using present-day optical lattices technology. This demonstrates not only that entanglement exists in solids but also that it can be used for quantum…
Monte Carlo study of the bimodal three-state Potts glass
1992
Employing Monte Carlo simulations, we compute the spin-glass susceptibility ${\mathrm{\ensuremath{\chi}}}_{\mathrm{SG}}$(T) of the three-state Potts glass model on a simple-cubic lattice for various temperatures and lattice sizes ranging from L=4 to 10. We use the discrete \ifmmode\pm\else\textpm\fi{}J distribution for the bonds. Comparing our results with a recent high-temperature series expansion, we find a systematic deviation at lower temperatures, which cannot be explained by finite-size effects in our data. The low-temperature behavior of ${\mathrm{\ensuremath{\chi}}}_{\mathrm{SG}}$(T) is compatible with d = 3 being the lower critical dimension of this model.