Related papers: Hard magnet coercivity
The development of permanent magnets containing less or no rare-earth elements is linked to profound knowledge of the coercivity mechanism. Prerequisites for a promising permanent magnet material are a high spontaneous magnetization and a…
The coercive field and angular dependence of the coercive field of single-grain Nd$_{2}$Fe$_{14}$B permanent magnets are computed using finite element micromagnetics. It is shown that the thickness of surface defects plays a critical role…
Multiscale simulation is a key research tool for the quest for new permanent magnets. Starting with first principles methods, a sequence of simulation methods can be applied to calculate the maximum possible coercive field and expected…
Magnetization reversal in permanent magnets occurs by the nucleation and expansion of reversed domains. Micromagnetic theory offers the possibility to localize the spots within the complex structure of the magnet where magnetization…
We formulated a technique which combines the first-principles, micromagnetic and microstructural calculations and allows us to study the nature of hysteretic phenomena in hard magnets. Two distinct sources of coercivity in polytwinned CoPt…
Magnetic hysteresis has become a crucial aspect for characterizing single-molecule magnets, but the comprehension of the coercivity mechanism is still a challenge. By using analytical derivation and quantum dynamical simulations, we reveal…
Magnetic reversal processes of a FePt/{\alpha}-Fe/FePt trilayer system with in-plane easy axes have been investigated within a micromagnetic approach. It is found that the magnetic reversal process consists of three steps: nucleation of a…
The performance of permanent magnets is intricately tied to their magnetic hysteresis loop. In this study, we investigate the heavy-fermion ferromagnet CeAgSb$_2$ through magnetization measurements under uniaxial stress. We observe a 2400 %…
Hard magnets with high coercivity, such as Nd2Fe14B and SmCo5 alloys, can maintain magnetisation under a high reverse external magnetic field and have therefore become irreplaceable parts in many practical applications. Molecular magnets…
The magnetic switching of ferromagnetic nanotubes is investigated as a function of their geometry. Two independent methods are used: Numerical simulations and analytical calculations. It is found that for long tubes the reversal of…
The magnetization reversal of Cu/NiFe and Nb/NiFe composite wires carrying AC current is studied. The frequency spectrum of a voltage induced in a pick-up coil wound around the wire is analyzed. The frequency spectrum is shown to consist of…
The maximum coercivity that can be achieved for a given hard magnetic alloy is estimated by computing the energy barrier for the nucleation of a reversed domain in an idealized microstructure without any structural defects and without any…
This thesis describes experimental and theoretical study of static and dynamic aspects of the irreversible magnetic behavior of high-Tc superconductors. Experimentally, conventional magnetometry and novel Hall-probe array techniques are…
The present article concludes that a ferromagnetic sample could be considered like a paramagnetic system where the role of magnetic moments plays magnetic domains. Based on this conclusion and taking into account presence of an anisotropic…
Magnetoresistance is a powerful probe for characterizing the intrinsic physics embedded in materials. Among its various manifestations, linear magnetoresistance has a long history and continues attracting research interest. In contemporary…
We consider the ways in which magnetically hard materials can be used as the working materials in thermomagnetic power generation (TMG) cycles in order to expand the area in the magnetisation vs. applied field ($M-H$) plane available for…
Multiscale phenomena which include several processes occuring simultaneously at different length scales and exchanging energy with each other, are widespread in magnetism. These phenomena often govern the magnetization reversal dynamics,…
Features of thermally-activated magnetization switching have been studied in a FeCoB nanomagnet using the N\'eel model. A method of a high-precision measurement of the coercive field, retention time, {\Delta} and the size of the switching…
A wide class of materials acquires magnetic properties due to particle interactions through exchange forces. These can be atoms and molecules composing the system itself, as in the case of numerous magnetic substances. Or these could be…
Magnetic nanoparticles (MNPs) have been proposed as an ultimate solution for diverse applications including nanomedicine and logic devices over decades. However, none has emerged revolutionary because realizing their magnetization response…