Sm{sub 2}Fe{sub 17} interstitial magnets (invited)
- Institut fuer Festkoerper- und Werkstofforschung Dresden e.V., 01171 Dresden (Germany)
Various processing routes for making permanent magnets based on interstitially modified Sm{sub 2}Fe{sub 17} have been recently developed. Zn bonding of coarse grained Sm{sub 2}Fe{sub 17}N{sub 3} gives coercivities {mu}{sub 0{ital J}}{ital H}{sub {ital c}} as high as 2.2 T. Effective methods to prepare highly coercive Sm{sub 2}Fe{sub 17}N{sub 3} powders for polymer bonding are mechanical alloying and rapid quenching. With the very simple method of additional milling of coarse grained nitrided powders we achieved {mu}{sub 0{ital J}}{ital H}{sub {ital c}}{approx_equal}1.5 T. A coercivity up to 3.5 T has been achieved by a modified HDDR procedure, reducing the particle size of the starting material by milling prior to the hydrogenation{endash}disproportionation{endash}desorption{endash}recombination (HDDR) treatment. This is attributed to a better control of two critical parameters, namely grain size and the amount of unrecombined {alpha}-Fe accompanying the intermediate TbCu{sub 7} structure-type phase. Resin bonded HDDR-Sm{sub 2}Fe{sub 17}N{sub 3} magnets show an unexpected high initial susceptibility. This may be due to a strong magnetic interaction of the grains. To develop coercivity in Sm{sub 2}Fe{sub 17}C{sub {ital y}{approx_gt}1} obtained by gas{endash}solid reactions of Sm{sub 2}Fe{sub 17} the same methods as those applied to Sm{sub 2}Fe{sub 17}N{sub 3} can be successfully used. Fully dense magnets with a coercivity up to 1.5 T were made from the interstitially as well as substitutionally modified compound Sm{sub 2}Fe{sub 15}Ga{sub 2}C{sub 2} by hot pressing of highly coercive powders. {copyright} {ital 1996 American Institute of Physics.}
- OSTI ID:
- 280030
- Report Number(s):
- CONF-951101-; ISSN 0021-8979; TRN: 9608M0084
- Journal Information:
- Journal of Applied Physics, Vol. 79, Issue 8; Conference: 40. conference on magnetism and magnetic materials, Philadelphia, PA (United States), 6-9 Nov 1995; Other Information: PBD: Apr 1996
- Country of Publication:
- United States
- Language:
- English
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