scholarly journals Simulating the Hysteretic Characteristics of Hard Magnetic Materials Based on Nd2Fe14B and Ce2Fe14B Intermetallics

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 518 ◽  
Author(s):  
Natalia B. Kolchugina ◽  
Mark V. Zheleznyi ◽  
Aleksandr G. Savchenko ◽  
Vladimir P. Menushenkov ◽  
Gennadii S. Burkhanov ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Magnetic Materials ◽  
Permanent Magnets ◽  
Mixed Valence ◽  
Hysteresis Loops ◽  
Anisotropy Field ◽  
Spin Reorientation ◽  
Cost Ratio ◽  
Hard Magnetic Materials ◽  
Negative Effect

The Ce2Fe14B intermetallic, like Nd2Fe14B, has the tetragonal Nd2Fe14B-type structure (space group P42/mnm), in which Ce ions have a mixed-valence state characterized by the coexistence of trivalent 4f1 and tetravalent 4f0 electron states. Despite the fact that the saturation magnetization, magnetic anisotropy field, and Curie temperature of the Ce2Fe14B intermetallic are substantially lower than those of Nd2Fe14B and Pr2Fe14B, Ce2Fe14B retains the capacity of being able to be used in the manufacturing of rare-earth permanent magnets. Moreover, at low temperatures, the anisotropy field of Се2Fe14B is higher than that of Nd2Fe14B, and Се2Fe14B does not undergo the spin-reorientation transition. In this respect, studies of (Nd, Ce)-Fe-B alloys, which are intended for the improvement of the service characteristics-to-cost ratio, are very relevant. A model and algorithm for calculating the hysteresis loops of uniaxial hard magnetic materials with allowance for the K1 and K2 (K2 > 0 and K1 > 0 and K1 < 0) magnetic anisotropy constants were developed and allowed us to obtain data on their effect on the parameters of hysteresis loops for a wide temperature range (0–300 K). The simulation and analysis of hysteresis loops of the quasi-ternary intermetallics (Nd1−хСех)2Fe14B (х = 0–1) was performed. Results of the simulation indicate that the alloying of the Nd2Fe14B intermetallic with Ce to x = 0.94 (1) does not completely eliminate the negative effect of spin-reorientation phase transition on the residual magnetization of the (Nd1−хCeх)2Fe14B intermetallic and (2) slightly decreases the slope of magnetization reversal curve.

scholarly journals Developing a reference material set for the magnetic properties of NdFeB alloy-based hard magnetic materials

2019 ◽  
Vol 15 (1) ◽  
pp. 21-27
Author(s):  
E. A. Volegova ◽  
T. I. Maslova ◽  
V. O. Vas’kovskiy ◽  
A. S. Volegov
Keyword(s):  
Magnetic Properties ◽  
Magnetic Materials ◽  
Permanent Magnets ◽  
Magnetic Loss ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Magnetic Hysteresis Loop ◽  
Magnetic Characteristics ◽  
Hard Magnetic Materials ◽  
Certified Values

Introduction The introduction indicates the need for the use of permanent magnets in various technology fields. The necessity of measuring the limit magnetic hysteresis loop for the correct calculation of magnetic system parameters is considered. The main sources of error when measuring boundary hysteresis loops are given. The practical impossibility of verifying blocks of magnetic measuring systems element-by-element is noted. This paper is devoted to the development of reference materials (RMs) for the magnetic properties of hard magnetic materials based on Nd2Fe14B, a highly anisotropic intermetallic compound.Materials and measuring methods Nd-Fe-B permanent magnets were selected as the material for developing the RMs. RM certified values were established using a CYCLE‑3 apparatus included in the GET 198‑2017 State Primary Measurement Standard for units of magnetic loss power, magnetic induction of constant magnetic field in a range from 0.1 to 2.5 T and magnetic flux in a range from 1·10–5 to 3·10–2 Wb.Results and its discussion Based on the experimentally obtained boundary hysteresis loops, the magnetic characteristics were evaluated, the interval of permitted certified values was set, the measurement result uncertainty of certified values was estimated, the RM validity period was established and the first RM batch was released.Conclusion On the basis of conducted studies, the RM type for magnetic properties of NdFeB alloy-based hard magnetic materials was approved (MS NdFeB set). The developed RM set was registered under the numbers GSO 11059–2018 / GSO 11062–2018 in the State RM Register of the Russian Federation.

Investigation of Possible Uniaxial Anisotropy in Co11Zr2 Magnetic Phase

2020 ◽  
Vol 65 (1-2) ◽  
pp. 11-17
Author(s):  
R. Hirian ◽  
◽  
P. Palade ◽  
‪A. Ciorîță ◽  
S. Macavei ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
High Temperature ◽  
Magnetic Anisotropy ◽  
Magnetic Materials ◽  
Mechanical Milling ◽  
Magnetic Phase ◽  
Uniaxial Anisotropy ◽  
High Temperature Annealing ◽  
Hard Magnetic Materials

"The Co11Zr2 magnetic phase was obtained by a combination of melting, mechanical milling and high temperature annealing. The structure and magnetic properties of the obtained material were investigated. Even though the samples possessed low coercivity, it was shown that they possess uniaxial anisotropy. Keywords: hard magnetic materials, magnetic anisotropy, mechanical milling, high temperature annealing "

Components of Magnetic Anisotropy of Soft Magnetic Nanocrystalline Fe-Based Films

2015 ◽  
Vol 233-234 ◽  
pp. 619-622 ◽  
Author(s):  
E.V. Harin ◽  
Elena N. Sheftel
Keyword(s):  
Magnetron Sputtering ◽  
Magnetic Anisotropy ◽  
Hysteresis Loops ◽  
Anisotropy Field ◽  
The Other ◽  
Structure Parameters ◽  
Soft Magnetic ◽  
Local Anisotropy ◽  
Magnetoelastic Anisotropy ◽  
Residual Macrostresses

We present quantitative evaluation results of micromagnetic structure parameters of nanocrystalline Fe, Fe95Zr5, Fe90N10, and Fe85Zr5N10films obtained by magnetron sputtering. It is shown that quantities of magnetocrystallineK1, magnetoelasticKME, magnetostaticKMS, and surfaceKa,Sanisotropies are components of experimentally measured effective local anisotropyKeff. The shape of the hysteresis loops of the films is determined by the presence of two main macroscopic effective magnetic anisotropies, one of which is the anisotropy field of stochastic domains, and the other is the magnetoelastic anisotropy field due to residual macrostresses.

scholarly journals Preparation and Magnetic Properties of CoFe2O4 Oriented Fiber Arrays by Electrospinning

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3860
Author(s):  
Chen Cheng ◽  
Jianfeng Dai ◽  
Zengpeng Li ◽  
Wei Feng
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Hysteresis Loop ◽  
Magnetic Materials ◽  
Magnetic Moment ◽  
Easy Axis ◽  
Great Influence ◽  
Hysteresis Loops ◽  
Strong Anisotropy ◽  
Fiber Arrays

The morphology of magnetic materials has a great influence on the properties, which is attributed to the magnetic anisotropy of the materials. Therefore, it is worth studying the fabrication of the aligned fiber and the change of its domain distribution. Nanoparticles and nanofibers were prepared by the hydrothermal and electrospinning methods, respectively. At the same time, the arranged nanofibers were collected by the drum collecting device. After the same annealing at 700 °C, it was found that the diameter of fibers collected by different collecting drums is similar. By studying the hysteresis loops of nanoarrays, it was found that they had strong anisotropy. The easy axis was parallel to the long axis, the Hc and Mr of the easy axis and the hard axis were 1330.5 Oe, 32.39 Am2/kg, and 857.2 Oe, 24.8 Am2/kg, respectively. Due to the anisotropy of the shape and the interaction between the particles, the Hc could not be enhanced. Therefore, the Ms and Hc of the nanoparticles were 80.23 Am2/kg and 979.3 Oe, respectively. The hysteresis loop and the change of magnetic moment during the demagnetization of the CoFe2O4 nanofiber array were simulated via micromagnetic software. The simulated Hc was 1480 Oe, which was similar to the experimental value.

The Exchange Energy Term and the Curling Reversal Mode in Hard Magnetic Materials Manufactured by Powder Metallurgy

2017 ◽  
Vol 899 ◽  
pp. 549-553
Author(s):  
Amilton Ferreira da Silva Jr. ◽  
Adriano S. Martins ◽  
Marcos Flavio de Campos
Keyword(s):  
Grain Size ◽  
Powder Metallurgy ◽  
Magnetic Materials ◽  
Anisotropy Field ◽  
Exchange Energy ◽  
Cosine Function ◽  
Hysteresis Curve ◽  
Energy Term ◽  
Hard Magnetic Materials ◽  
Exchange Effects

The curling reversal mode is discussed, with emphasis on the assumptions of the model, many of them unrealistic. The curling mode assumes the Bloch approximation, where a cosine function is approximated by a polynomial of second order. It is argued that if the curling model takes place, this could affect the anisotropy field, and then the anisotropy field would be function of the grain size, but this is not observed. Exchange effects may affect hysteresis curve, as discussed in the SW-CLC model.

scholarly journals A Novel Computational Method to Identify/Analyze Hysteresis Loops of Hard Magnetic Materials

2021 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
Alessandro Giuseppe D’Aloia ◽  
Antonio Di Francesco ◽  
Valerio De Santis
Keyword(s):  
Magnetic Materials ◽  
Hysteresis Loops ◽  
Computational Method ◽  
Large Temperature ◽  
Preisach Model ◽  
Ndfeb Magnet ◽  
Hard Magnetic Materials ◽  
Differential Formulation ◽  
Computational Performance ◽  
Neodymium Magnets

In this study, a novel computational method capable of reproducing hysteresis loops of hard magnetic materials is proposed. It is conceptually based on the classical Preisach model but has a completely different approach in the modeling of the hysteron effect. Indeed, the change in magnetization caused by a single hysteron is compared here to the change in velocity of two disk-shaped solids elastically colliding with each other rather than the effect of ideal geometrical entities giving rise to so-called Barkhausen jumps. This allowed us to obtain a simple differential formulation for the global magnetization equation with a significant improvement in terms of computational performance. A sensitivity analysis on the parameters of the proposed method has indeed shown the capability to model a large class of hysteresis loops. Moreover, the proposed method permits modeling of the temperature effect on magnetization of neodymium magnets, which is a key point for the design of electrical machines. Therefore, application of the proposed method to the hysteresis loop of a real NdFeB magnet has been proven to be very accurate and efficient for a large temperature range.

Processing Sm-Fe(Ta)-N hard magnetic materials

1999 ◽  
Vol 577 ◽  
Author(s):  
K Žužek ◽  
PJ Mcguiness ◽  
S Kobe
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Permanent Magnets ◽  
Processing Parameters ◽  
High Energy ◽  
Small Particle Size ◽  
Optimum Conditions ◽  
Hard Magnetic Materials ◽  
Negative Effect ◽  
Cast Alloys

ABSTRACTSmFe based alloys interstitially modified with nitrogen are potential candidates for high energy permanent magnets. In order to obtain the optimum properties a thorough understanding of the starting material and processing parameters is required. The microstructures of two cast alloys of composition Sm13.8Fe82.2 Ta4.0 and Sm13.7 Fe86.3 were carefully examined with a SEM equipped with EDX and the exact stoichiometries of the phases were determined. The SmFeTa material was found to contain significant amounts of TaFe2as well as the Sm2Fe17, SmFe2, SmFe3 phases observed in the SmFe material but without the a-iron dendrites which are characteristic of the latter material. The optimum conditions necessary to provide the highest coercivities using the conventional HDDR process, and for the HDDR process combined with pre-milling were investigated. The coercivities obtained after using the HDDR process and subsequent nitriding were 680 kA/m for the SmFeTaN and 360 kA/m for the SmFeN samples. Significantly higher coercivites of 1000 kA/m for SmFeN and 1275 kA/m for SmFeTaN were achieved by reducing the particle size with milling prior to the HDDR process.The better coercivities obtained with the Ta containing sample were found to be due to the presence of a much smaller amount of a. The milling prior to the HDDR treatment improves the magnetic properties because of the small particle size which prevents the grains growing too large, with their consequent very negative effect on the coercivity.

scholarly journals Anisotropy of Magnetic Properties in Textured Materials

1989 ◽  
Vol 11 (2-4) ◽  
pp. 93-105 ◽  
Author(s):  
J. A. Szpunar
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Magnetic Materials ◽  
Hard Magnetic Materials ◽  
Short Survey ◽  
Textured Materials

A short survey is presented of techniques and methods used to correlate the texture with the magnetic anisotropy of various properties of soft and hard magnetic materials. Also, examples of magnetic materials are discussed with emphasis on techniques of processing which optimize the texture.

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