Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

The Influence of Composition and Field Annealing on Magnetic Properties of FeCo-Base Amorphous and Nanocomposite Alloys



Freemon Johnson, C Y. Um, M E. McHenry, H Garmestani


We report the influence of composition and very high transverse field annealing on the magnetic properties and structure of four FeCo-based amorphous and nanocomposite alloy compositions. The compositions (Fe50Co50)89Zr7B4 and (Fe65Co35)89Zr7B4 investigated changing the Fe:Co ratio from 50:50 to 65:35. (Fe50Co50)85Zr2Nb4B8.5 investigated Nb substitution for Zr in an FeCo-base alloy. This substitution is shown to increase the magnetostrictive constant, ?S, of the nanocomposite alloy from 36 ppm to 54 ppm. The composition (Fe65Co35)84Cr5Zr7B4 investigated the influence of Cr on intergranular coupling across the amorphous matrix. Samples of each composition were annealed in the amorphous state at 300 C and in the nanocomposite state at 600 C. Field annealing was performed in 17 T transverse field in an inert atmosphere. Magnetic properties were measured between 60 Hz to 1 MHz with an automatic recording hysteresisgraph. Quasistatic magnetic properties were measured with a vibrating sample magnetometer. The mass specific power loss of the alloys decreased with field annealing in both the nanocomposite and amorphous states for some frequency and induction combinations. Furthermore, the hysteresis loops are sheared after field annealing, indicating a transverse magnetic anisotropy. The nanocomposite (Fe50Co50)85Zr2Nb4B8.5 composition has a lower relative permeability than the other compositions. P.A.C.S. Codes
Journal of Applied Physics


high transverse field annealing, hysteresisgraph, magnetic properties, magnetostrictive, nanocomposite, Quasistatic magnetic properties


Johnson, F. , Um, C. , McHenry, M. and Garmestani, H. (2008), The Influence of Composition and Field Annealing on Magnetic Properties of FeCo-Base Amorphous and Nanocomposite Alloys, Journal of Applied Physics (Accessed July 15, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created October 16, 2008