Temperature and field direction dependences of first-order reversal curve (FORC) diagrams of hot-deformed Nd-Fe-B magnets

Takahiro Yomogita, Satoshi Okamoto, Nobuaki Kikuchi, Osamu Kitakami, Hossein Sepehri-Amin, Tadakatsu Ohkubo, Kazuhiro Hono, Takahiro Akiya, Keiko Hioki, Atsushi Hattori

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

First-order reversal curve (FORC) diagram has been previously adopted for the analyses of magnetization reversal process and/or quantitative evaluation of coercivity and interaction field dispersions in various magnetic samples. Although these kinds of information are valuable for permanent magnets, previously reported FORC diagrams of sintered Nd-Fe-B magnets exhibit very complicated patterns. In this paper, we have studied the FORC diagrams of hot-deformed Nd-Fe-B magnets under various conditions. Contrary to the previous reports on sintered Nd-Fe-B magnets, the FORC diagram of the hot-deformed Nd-Fe-B magnet exhibits a very simple pattern consisting of a strong spot and a weak line. From this FORC diagram pattern, it is revealed that the coercivity dispersion of the hot-deformed Nd-Fe-B magnets is surprisingly small. Moreover, this feature of the FORC diagram pattern is very robust and unaffected by changes in various conditions such as grain boundary diffusion process, temperature, and field direction, whereas these conditions significantly change the coercivity and the shape of magnetization curve. This fact indicates that the magnetization reversal process of the hot-deformed Nd-Fe-B magnets is almost unchanged against these conditions.

Original languageEnglish
Pages (from-to)110-115
Number of pages6
JournalJournal of Magnetism and Magnetic Materials
Volume447
DOIs
Publication statusPublished - 2018 Feb 1

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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