# Features of the magnetization reversal processes in sintered permanent magnets Nd-Fe-B and Sm-Co type https://mdr.nims.go.jp/datasets/001e18e8-c751-4d9f-a6a2-961544528914 ## File - [REPM2025_P1-19_Urzhumtsev.pdf](https://mdr.nims.go.jp/filesets/3c1d1354-0a41-49a6-b175-da145e6ce23e/download) ([Detail](https://mdr.nims.go.jp/filesets/3c1d1354-0a41-49a6-b175-da145e6ce23e.md)) ## Id 001e18e8-c751-4d9f-a6a2-961544528914 ## Local identifier ## Visibility open_to_public ## State published ## Created at 2025-08-25T02:36:17.780353Z ## Updated at 2025-09-11T07:30:46.206514Z ## Published at 2025-09-11T07:19:58.234487Z ## Doi https://doi.org/10.48505/nims.5666 ## First published url ## Date published ## Recorded date published ## Resource type conference_poster ## Manuscript type na ## Collection - id: d28f086a-61aa-4bc7-bcae-5a1078cbc6c7 identifier: https://mdr.nims.go.jp/pid/d28f086a-61aa-4bc7-bcae-5a1078cbc6c7 title: The 28th International Workshop on Rare Earth and Future Permanent Magnets and Their Applications (REPM2025) ## Title - title: Features of the magnetization reversal processes in sintered permanent magnets Nd-Fe-B and Sm-Co type title_type: original lang: en ## Description - description: "In the modern technology industry, there are a large number of areas for the application of hard magnetic materials, the main volumes of consumption of which fall on the energy sector for electric motors and generators. The issue of magnetization reversal mechanisms in sintered permanent magnets (PM) of the Nd-Fe-B and Sm-Co type remains controversial. The main reason for this is the complex heterogeneous micro- and nanostructure formed during sintering, the properties of which are difficult to describe using structural analysis and numerical modeling.\r\nThe paper presents a number of approaches to measuring and assessing magnetic properties that allow us to determine the role of each of the magnetization reversal mechanisms in the formation of the coercivity of the most common commercial magnets of the N35, N48, N48SH and Sm(Co, Fe, Zr, Cu)Z grades. \r\nMagnetic measurements of the initial magnetization and susceptibility curves were carried out on MPMS XL 7 in fields up to 7 T. Magnetic susceptibility was measured in alternating AC magnetic field with an amplitude h ~ = 3.7 Oe and a frequency f = 7 Hz. Partial hysteresis loops were measured using a PPMS DynaCool with a VSM setup attachment in a field of up to 9 T with a step of 1 kOe.\r\nThe study analyzes initial magnetization curves σ(H) and σr(H) from a thermally demagnetized state, magnetic susceptibility curves χ(H) and χr(H), angular dependences of coercivity Hc(Θ) within the framework of the Kondorsky and Stoner-Wohlfarth models, assesses the reversible and irreversible contribution to magnetization, and evaluates the role of intergranular magnetostatic interaction. The results of the presented magnetometric methods are combined into a general concept for assessing the role of pinning, nucleation and coherent rotation in magnetization reversal processes for sintered PM. The considered methods of analysis show that the mechanism of magnetization reversal in permanent magnets based on the Nd2Fe14B phase is more complex than predicted by purely nucleation or pinning models [1]. A similar picture is observed in magnets of Sm(Co, Fe, Zr, Cu)Z type [2], but the effects of changes in magnetic susceptibility, reversible contribution to magnetization and the role of magnetostatic interaction are manifested approximately an order of magnitude weaker than in Nd-Fe-B magnets.\r\nThe study showed that the approach under consideration for assessing the mechanism of formation of a high-coercivity state is an effective tool that complements such methods as microstructural analysis and numerical modeling and allows predicting the prevailing role of the pinning or nucleation. For example, it has been shown that in the Nd-Fe-B PM N35 grade magnetization reversal almost entirely through domain wall movements, while N48SH behaves close-up to nucleation process. It was found that the magnetization reversal mechanisms in sintered rare-earth permanent magnets can indicate themselves in a very diverse manner and are largely determined by the history of the creation of a given magnet and differ from PM the same type, but different grades. \r\nThis work was financially supported by FEUZ-2024-0060.\r\n\r\nReferences\r\n1. Urzhumtsev, A. N., Maltseva, V. E., Yarkov, V. Y., Volegov, A. S. (2022). A modified Kondorsky model for describing the magnetization reversal processes in Nd–Fe–B permanent magnets. Physics of Metals and Metallography, 123(11), 1054-1060.\r\n2. Urzhumtsev, A., Maltseva, V., Volegov, A. (2022). Magnetization reversal processes in sintered permanent magnets Sm(Co, Fe, Zr, Cu)z. Journal of Magnetism and Magnetic Materials, 551, 169143." description_type: abstract lang: en ## Creator - name: Andrey Urzhumtsev role: author organization: Ural Federal University, Russia - name: Viktoria Maltseva role: author organization: Ural Federal University, Russia - name: Alexey Volegov role: author organization: Ural Federal University, Russia ## Contact agent ## Publisher organization: National Institute for Materials Science (NIMS) ## Managing organization ## Keyword - subject: REPM2025 schema: not_defined - subject: permanent magnets schema: not_defined - subject: coercivity schema: not_defined - subject: magnetisation reversal processes schema: not_defined - subject: pinning schema: not_defined - subject: nucleation schema: not_defined ## Rights - identifier: https://creativecommons.org/licenses/by/4.0/ ## Other identifier(s) ## Data origin - data_origin_type: other ## Embargo ## Journal ## Conference name: REPM2025 start_date: 2025-07-27 end_date: 2025-07-31 identifier: https://www.nims.go.jp/mmu/repm2025/ ## Related item ## Funding ## Instrument ## Instrument operator ## Instrument managing organization ## Measurement method ## Specimen ## Chemical composition ## Structure for specimen ## Structural feature for specimen ## Specific property for specimen ## Process for specimen treatment ## Computational method ## Energy level/transition state ## Software ## Custom property ## Fileset - id: 3c1d1354-0a41-49a6-b175-da145e6ce23e filename: REPM2025_P1-19_Urzhumtsev.pdf content_type: application/pdf size: 2165133 md5: 4f74001a0902725b0a064910b65ea46d ## Thumbnail fileset_id: 3c1d1354-0a41-49a6-b175-da145e6ce23e filename: REPM2025_P1-19_Urzhumtsev.pdf