High Saturation Magnetization and Soft Magnetic Properties of bcc Fe-Zr-B and Fe-Zr-B-M (M = Transition Metal) Alloys with Nanoscale Grain Size

K. Suzuki, N. Kataoka, A. Inoue, T. Masumoto, A. Makino

Research output: Contribution to journalArticleResearchpeer-review

363 Citations (Scopus)


A mostly single bcc phase with nanoscale grain sizes of 10 to 20 nm was found to form by annealing amorphous Fe-Zr-B, Fe-Zr-B-Cu and Fe-Zr-B-Cu-M (M = Hf, Nb or Ta) alloys for 3.6 ks in the range of 750 to 900 K. The composition range of the bcc phase extends from 5 to 7%Zr and 1 to 8%B for the Fe-Zr-B system and 5 to 8%Zr and 1 to 16%B for the Fe-Zr-B-l%Cu system. The bcc alloys exhibit high permeability (μc) above 10000 at 1 kHz combined with high saturation magnetization (Bs) above 1.5 T and the highest values reach 14000 and 1.70 T for Fe91Zr7B2 and 20000 and 1.55 T for Fe87Zr7B5Cu1. The addition of 1 at% Cu causes an enhancement of μc through the decrease of the bcc grain size from 20 to 10 nm, in addition to an extension of the formation range of the bcc phase. It should be noted that the highest Bs value is almost comparable to that for Fe-6.5 mass% Si and considerably higher than those of other practical soft magnetic materials while the μc values are much higher than that for the Fe-Si alloy. Accordingly, the combined characteristics of high Bs and μc values for the bcc Fe-Zr-B base alloys allow us to expect a subsequent development as a novel soft magnetic material.

Original languageEnglish
Pages (from-to)93-102
Number of pages10
JournalMaterials Transactions, JIM
Issue number1
Publication statusPublished - 1 Jan 1991
Externally publishedYes


  • amorphous phase
  • bcc alloy
  • crystallization
  • high magnetization
  • iron-zirconium-boron system
  • nanoscale grain structure
  • permeability
  • soft magnetism

Cite this