Magnetic study of Hitperm alloys (Fe0.5Co0.5)1-x-y-zMxByCuz(M = Hf, Zr, Nb)

✍ Scribed by Pękała, M. ;Kowalczyk, M. ;Kulik, T.

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 272 KB
• Volume: 203
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200563129

✦ Synopsis

Abstract

A family of the Hitperm alloys (Fe~0.5~Co~0.5~)~1–x –y –z~ M~x~ B~y~ Cu~z~ (M = Hf, Zr, Nb) produced in an argon atmosphere as amorphous ribbons with 0.025 mm thickness are investigated up to 1200 K. The partial replacement of Fe by Co with optimal Fe~0.5~Co~0.5~ ratio increases the Curie temperature of the amorphous phase and the magnetic moment per formula unit. The early stages of crystallization can be observed by magnetization measurements. Alloys subjected to the first controlled crystallization stage are built of bcc‐(Fe,Co) nanocrystals that are homegeneously embedded in the amorphous matrix. Mean grain sizes are about 11 nm. These two‐phase alloys exhibit good soft magnetic properties with the relatively low coercive fields up to 50 A/m. Hafnium and hafnium/zirconium mixture are found to be the best inhibitors of the nanograin growth resulting in the best soft magnetic parameters. Alloys with niobium exhibit lower thermal stability and higher coercive fields. The correlation between the structure evolution and the magnetic properties is analysed and discussed. Conditions for optimum heat treatment are also determined. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)