An official website of the United States government
Here’s how you know
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.
Amorphous FeCoCrZrB Ferromagnets for Use as High-Temperature Magnetic Refrigerants
Published
Author(s)
Freemon Johnson, Robert D. Shull
Abstract
Magnetic metallic glasses, having large magnetic moments and high Curie Temperatures (TC), have not been widely studied as magnetic refrigerants. In this study, we report on the magnetocaloric effects of five FeCoCrZrB amorphous alloys ((FexCoyCrz)91Zr7B2, with Fe:Co:Cr ratios of 100:0:0, 90:15:5, 85:5:10, and 75:15:10 chosen for efficiently surveying the high TC metallic glass composition surface. Magnetic isotherms were measured at 25 K intervals from 25 to 525 K. The entropy change (?S) due to the magnetocaloric effect was computed by integrating the magnetic isotherms. The refrigeration capacity (RC) was computed by the Wood and Potter method. At 5 Tesla the FeCoCrZrB alloys have RC values of 240-320 J/kg; at 1 Tesla the alloys have values of 32-54 J/kg. The RC values favorably compare with values reported for other refrigerant materials. The peak ?S temperature depends strongly on composition, varying from 200 to 450 K. The wide flexibility in choosing amorphous alloy compositions allows them to be fine tuned for multi-stage high temperature refrigerators. The saturation magnetization at 25 and 300 K and Curie temperatures are also reported for the five alloys.
amorphous magnets, magnetic measurements, magnetic refrigeration, magnetocaloric effect
Citation
Johnson, F.
and Shull, R.
(2006),
Amorphous FeCoCrZrB Ferromagnets for Use as High-Temperature Magnetic Refrigerants, Journal of Applied Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=853403
(Accessed December 3, 2024)