Ferromagnetic decagonal Mn-Al-Ge-B-Fe quasicrystals with high coercive force

Yoshihiko Yokoyama, Akihisa Inoue

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


A ferromagnetic decagonal phase with high coercive forces exceeding 80kA/m (1 kOe) was found to form in rapidly solidified Mn45-x,Al25Ge15B15Fex (x=10 and 15 at%) alloys. The decagonal alloy containing 15 at%Fe consists of fine grains with sizes of 5 to 20 nm and has the periodic lattice spacing of 1.2 nm along the c-axis direction. Furthermore, the decagonal phase contains a high density of internal defects and the electron diffraction patterns consist of reflection spots with significant streaks along the < 100000) direction in the quasilattice a-b plane. The decagonal Mn30Al25Ge15B15Fe15 alloy exhibits ferromagnetic properties of 2.89 × 10-5 Wb m/kg for magnetization under a field of 1432 kA/m (J1432), 1.38 × 10-5 Wb m/kg for remanence (Br), 114 kA/m for intrinsic coercive force (1Hc), 1.4kJ/m3 for maximum energy product (B//)mas and 620 K for Curie temperature (7;). The high coercive force is presumably due to the formation of the nanoscale ferromagnetic decagonal grains containing a high density of phason defects. The first success of synthesizing the ferromagnetic decagonal alloy with the hard magnetic characteristics is encouraging for future progress of quasicrystalline alloys as a new type of engineering material.

Original languageEnglish
Pages (from-to)559-563
Number of pages5
JournalMaterials Transactions, JIM
Issue number4
Publication statusPublished - 1996
Externally publishedYes


  • Decagonal phase
  • Ferromagnetic quasicrystal
  • Hard magnetic property
  • Large coercive force
  • Manganese base alloy
  • Nanoscale decagonal grain
  • Rapid solidification

ASJC Scopus subject areas

  • Engineering(all)


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