We have studied the magnetization dynamics of disk array La0.7Sr0.3MnO3 ferromagnetic by means of timeresolved micromagnetic simulation. The coercivity field (Hc) is assumed depend on the interdisk distance. Meanwhile, the distribution of C-states of disk array, in the along of the same diagonal, exhibits an opposite state which is called positive Cstates and negative C-states. Along of the sam...

We analyze low field hysteresis close to the demagnetized state in disordered ferromagnets using the zero temperature random-field Ising model. We solve the demagnetization process exactly in one dimension and derive the Rayleigh law of hysteresis. The initial susceptibility a and the hysteretic coefficient b display a peak as a function of the disorder width. This behavior is confirmed by nume...

*Correspondence: Christopher H. Marrows, School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK e-mail: [email protected] We have studied experimentally the states formed in artificial square ice nanomagnet systems following demagnetization in a rotating in-plane applied magnetic field that reduces to zero in a manner that is linear in time. The final states are found to ...

A self-consistent mean-field theory explaining the thermal remagnetization (TR) of polycrystalline permanent magnets is given. The influence of the environment of a grain is treated by an inclusion approximation, relating the field inside the grain to the local field outside by means of an internal demagnetization factor n. For the switching fields and the fluctuations of the local fields aroun...

Abstract. This work presents unprecedented, high-resolution palaeomagnetic data from the sedimentary record of Lake Levinson-Lessing, deepest lake in northern central Siberia. Palaeomagnetic analyses were carried out on 730 discrete samples upper 38 m 46 long core Co1401, which was recovered part lake. Alternating field demagnetization experiments to obtain characteristic remanent demagnetizati...

[1] The ‘‘hard’’ isothermal remanent magnetization (HIRM) and the S-ratio are widely used in environmental magnetism to quantify the absolute and relative concentrations, respectively, of antiferromagnetic minerals (hematite and goethite) in mineral mixtures. We demonstrate that synthetic Al-substituted hematite and goethite exhibit a wide range of coercivities, which significantly influences t...

To demagnetize small-scale objects (dimensions less than 1 m) fabricated from ferromagnetic materials, it is standard practice to expose the object to a continuous ac applied magnetic field with a steadily decaying amplitude. For objects of dimensions greater than 10 m, there are problems of scale, and a stepwise procedure is preferred. We have simulated two different stepwise demagnetization t...

Demagnetization, commonly employed to study ferromagnets, has been proposed as the basis for an optimization tool, a method to find the ground state of a disordered system. Here we present a detailed comparison between the ground state and the demagnetized state in the random field Ising model, combing exact results in d = 1 and numerical solutions in d = 3. We show that there are important dif...

We consider the adiabatic demagnetization in the rotating reference frame (ADRF) of a system of dipolar coupled nuclear spins s = 1/2 in an external magnetic field. The demagnetization starts with the offset of the external magnetic field (in frequency units) from the Larmor frequency being several times greater than the local dipolar field. For different subsystem sizes, we have found from num...