Electromagnetic microwave absorption of α-Fe microstructure produced by disproportionation reaction of Sm2Fe17 compound

Toru Maeda, Satoshi Sugimoto, Toshio Kagotani, David Book, Motofumi Homma, Hiroyasu Ota, Yuji Houjou

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19 Citations (Scopus)


The electromagnetic wave absorption properties of a magnetic powder with a fine α-Fe structure, produced by the disproportionation of Sm2Fe17, were investigated in the GHz frequency range. A fine, sub-micrometre α-Fe/SmH2 structure was formed from the Sm2Fe17 compound after disproportionation in a hydrogen atmosphere. The grain size of the α-Fe phase was calculated by X-ray diffraction line broadening analysis, to be about 30 nm. In this way, a magnetic powder with a fine structure of α-Fe was obtained. This powder was then heated in air in order to oxidize the SmH2, with the result that an α-Fe/SmO two-phase microstructure was obtained. Toroidally shaped epoxy-resin composites were made from this powder, and the microwave absorption properties of these samples were measured. As a result, the disproportionated samples (heated in hydrogen at 873 K for 1 hour, milled for 30 minutes and oxidized at 473 K for 2 hours in the air) exhibited electromagnetic wave absorption (R.L.<-20 dB) in the frequency range 0.75 to 1.3GHz, for absorber thicknesses ranging from 12.5 to 7.5 mm, respectively. An undisproportionated sample did not show any electromagnetic wave absorption in this frequency range.

Original languageEnglish
Pages (from-to)1172-1175
Number of pages4
JournalUnknown Journal
Issue number9
Publication statusPublished - 2000 Sep

ASJC Scopus subject areas

  • Engineering(all)

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