Structure change in Sm–Fe–B–Ti permanent magnet materials induced by HDDR process

Autor:	Kenji Hiraga, Zheng Liu, Tetsu Ohsuna, Masahiro Tobise
Rok vydání:	1999
Předmět:	Diffraction Materials science Mechanical Engineering Alloy Metals and Alloys Titanium alloy Electron Crystal structure engineering.material Crystallography Mechanics of Materials Transmission electron microscopy Lattice (order) Magnet Materials Chemistry engineering
Zdroj:	Journal of Alloys and Compounds. 288:277-285
ISSN:	0925-8388
DOI:	10.1016/s0925-8388(99)00099-7
Popis:	The structures of Sm8.3Fe85.2B2.0Ti4.5 and Sm9.4Fe84.1B2.0Ti4.5 alloys, which show superior properties as isotropic permanent magnets after a hydrogenation–disproportionation–desorption–recombination (HDDR) process followed by a nitridation, have been investigated by transmission electron microscopy, and electron and X-ray diffraction, paying particular attention to the structural changes induced by the HDDR process. It is found that a hexagonal Th2Ni17-type structure, observed in both alloys, with an approximate composition Sm(Fe,Ti)9.5 before the HDDR process, transforms to a rhombohedral Th2Zn17-type structure with a composition Sm(Fe,Ti)8.5 after the HDDR process. The Ti content in the hexagonal Th2Ni17-type structure is higher than that in the rhombohedral structure. The hexagonal Th2Ni17-type and rhombohedral Th2Zn17-type structures in the Sm9.4Fe84.1B2.0Ti4.5 alloy have lattice parameters a=0.85103(3) nm and c=0.83820(5) nm, and a=0.85549(3) nm and c=1.24826(9) nm, respectively, and show the relationship ahex 1/3crhomb.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::ff1f1c171ce19a06ddcba914236e9f2a https://doi.org/10.1016/s0925-8388(99)00099-7 Zobrazit plný text záznamu Full Text from ScienceDirect