First-order reversal curve analysis of a Nd-Fe-B sintered magnet with soft X-ray magnetic circular dichroism microscopy

Miyazawa, Kazunori; Okamoto, Satoshi; Yomogita, Takahiro; Kikuchi, Nobuaki; Kitakami, Osamu; Toyoki, Kentaro; Billington, David P.; Kotani, Yoshinori; Nakamura, Tetsuya; Sasaki, Taisuke; Ohkubo, T.; Hono, K.

doi:10.1016/j.actamat.2018.09.053

Cited by 29 publications

(7 citation statements)

References 34 publications

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“…In particular, high chemical and thermal stabilities, good display performance and a large magneto-crystalline anisotropy (MAE) of the ordered binary FePt MnPt, and CrPt 3 alloys made them superior to other binary alloys used in magneto-optical recording devices [1,2,3,4] communication devices [5], optical filters [6], biomedical applications [7] and spintronic applications [8,9]. The FePt and MnPt binary alloys are considered as potential candidates for state-of-art spintronic applications like magnetic random access memory (MRAM) [10,11] and drivers in micro-and nano-electromechanical systems (MEMS/NEMS) [12,13,14,15,16]. It has been reported that high-purity L1 0 FePt NPs could be obtained by controlling the proportion of iron and platinum only in the vicinity of the equiatomic composition [17].…”

Section: Introductionmentioning

confidence: 99%

Structural, electronic and magnetic properties of the ordered binary FePt, MnPt, and CrPt3 alloys

Alsaad

Obeidat

2020

Heliyon

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We perform ab initio simulations to investigate the structural, electronic and magnetic properties of the ordered binary FePt, MnPt, and CrPt3 alloys. In particular, equilibrium structural lattice parameters, electronic properties such as density of states (DOS), partial density of states (PDOS) and electronic band structure of each binary alloys are investigated and interpreted. Moreover, the magneto-crystalline anisotropy energies (MAE) are calculated. We found MAE values of FePt, MnPt and CrPt 3 ordered alloys to be 2.66, 0.46 and 0.42 meV/f.u., respectively, corresponding to magneto-crystalline anisotropy constant K of 7.6 Â 10 7 , 1.3 Â 10 7 and 1.1 Â 10 7 erg/cm 3 , respectively. The large MAE and K values reveal that FePt, MnPt and CrPt 3 binary alloys are eligible to be key components in magneto-optical and opto-electronic devices. In addition, we estimated the Curie temperatures of the three ordered alloys from exchange energy. We found the T C of L1 0 -FePt, L1 0 -MnPt and L1 2 CrPt 3 to be 955 K, 989 K and 762 K, respectively. The high Curie temperatures obtained enable the ordered alloys to serve as write assist in Heat-Assisted Magnetic Recording (HAMR). We believe that our findings would pave the way to fabricate bulk and thin films based on the ordered binary FePt, MnPt, and CrPt 3 ordered alloys that have attractive electronic and magnetic properties.

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Section: Introductionmentioning

confidence: 99%

Structural, electronic and magnetic properties of the ordered binary FePt, MnPt, and CrPt3 alloys

Alsaad

Obeidat

2020

Heliyon

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“…Experimental data of the weight distributions can have negative values for some parts of the distribution function [ 219 , 220 ]. This has been observed for permanent magnets of NdFeB [ 126 , 127 , 128 , 129 ] as well as in geology in magnetite rocks [ 219 , 221 ]. The reason behind this type of negative values can be explained by the simplified assumption of the Preisach model and that it cannot describe all types of hysteresis curves.…”

Section: Negative Values In the Preisach Distributionmentioning

confidence: 58%

“…Even if the method is mostly applied for soft magnetic iron, it can be used for modeling the hysteresis of hard magnetic materials. The Preisach model has been applied for hard magnetic materials for modeling of Alnico by Coulson et al [ 123 ], Ba-Ferrite by Michelakis et al [ 124 ], NdFeB by Rosu et al [ 125 ] and others [ 126 , 127 , 128 , 129 ], SmCo by Cornejo et al [ 130 ] and also for semi-hard magnetic material, such as Alnico-5, by Rahman et al [ 131 ].…”

Section: Preisach Modelmentioning

confidence: 99%

“…One example of a material where nucleation is a dominating hysteresis mechanism is NdFeB [ 222 , 223 ]. Furthermore, it is clear that NdFeB have FORCs that can not be modeled by a proper Preisach model, since it gives undesired negative values in the Preisach distribution [ 126 , 127 , 128 , 129 ].…”

Section: Negative Values In the Preisach Distributionmentioning

confidence: 99%

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Review of Play and Preisach Models for Hysteresis in Magnetic Materials

Mörée

Leijon

2023

Materials

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This paper studies the properties of the Preisach model and the play model, and compare their similarities. Both are history-dependent hysteresis models that are used to model magnetic hysteresis. They are described as discrete sums of simple hysteresis operators but can easily be reformulated as integral equations of continuous distribution functions using either a Preisach weight distribution function or a play distribution function. The models are mostly seen as phenomenological or mathematical tools but can also be related to friction-like pinning of domain-wall motions, where Rayleigh’s law of magnetic hysteresis can be seen as the simplest case on either the play model or the Preisach model. They are poor at modeling other domain behavior, such as nucleation-driven hysteresis. Yet another hysteresis model is the stop model, which can be seen as the inverted version of the play model. This type of model has advantages for expressions linked to energy and can be related to Steinmetz equation of hysteresis losses. The models share several mathematical properties, such as the congruency property and wiping-out property, and both models have a history of dependence that can be described by the series of past reversal points. More generally, it is shown that the many models can be expressed as Preisach models, showing that they can be treated as subcategories of the Preisach type models. These include the play model, the stop model and also the alternative KP-hysteron model.

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“…[18][19][20] Fortunately, a new and emerging method, the first-order-reversal-curve (FORC) diagram, can be applied to study the demagnetization process of hysteresis materials, which could provide full mapping of magnetic switching, magnetic interactions, and the magnetic domain nature in the magnetic system. [20][21][22][23][24] The precursors with precise composition were critical to the preparation of Nd 2 Fe 14 B-based nanostructures of the desired compositions. Besides, the scanning electron microscope (SEM) images (Fig.…”

Section: Introductionmentioning

confidence: 99%

First-order-reversal-curve analysis of rare earth permanent magnet nanostructures: insight into the coercivity enhancement mechanism through regulating the Nd-rich phase

Zhu

Wang

et al. 2021

Inorg. Chem. Front.

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First-order reversal curve analysis of a Nd-Fe-B sintered magnet with soft X-ray magnetic circular dichroism microscopy

Cited by 29 publications

References 34 publications

Structural, electronic and magnetic properties of the ordered binary FePt, MnPt, and CrPt3 alloys

Structural, electronic and magnetic properties of the ordered binary FePt, MnPt, and CrPt3 alloys

Review of Play and Preisach Models for Hysteresis in Magnetic Materials

First-order-reversal-curve analysis of rare earth permanent magnet nanostructures: insight into the coercivity enhancement mechanism through regulating the Nd-rich phase

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