Effect of Fe, Cu, Zr, and Ti on the magnetic properties of SmCo-1:7 magnets

Author

Venkatesan, M. ; Rhen, F.M.F. ; Gunning, R. ; Coey, J.M.D.

Author_Institution

Phys. Dept., Trinity Coll., Dublin, Ireland

Volume

38

Issue

5

fYear

2002

fDate

9/1/2002 12:00:00 AM

Firstpage

2919

Lastpage

2921

Abstract

The effect of Fe, Cu, Zr, and Ti substitution on magnetic properties of SmCo 1:7 magnets at temperatures up to 500°C were studied. As-milled amorphous Sm(Co,Fe,Cu,Ti-Zr)₇ magnets crystallized in the TbCu₇-type structure after annealing at 750°C for 2 h. A room-temperature intrinsic coercivity of around 2.5 T is obtained for compositions SmCo_6.4 Zr_0.2Ti_0.4 and SmCo_6.4Fe_0.1Zr_0.1Ti_0.4. The high coercivity of the ball-milled SmCo_7-xTi_x magnets is attributed to the strong pinning of the walls of the "interaction domains" by the network of grain boundaries between the nanocrystalline grains. The virgin curve of the ball-milled samples is suggestive of strong domain wall pinning.

Keywords

Curie temperature; alloying additions; annealing; cobalt alloys; coercive force; ferromagnetic materials; grain size; magnetic domain walls; magnetic hysteresis; magnetisation reversal; nanostructured materials; permanent magnets; powder metallurgy; samarium alloys; 500 C; Curie temperature; SmCo₇; X-ray diffraction; anisotropy field; annealing; ball-milled magnets; demagnetization curve; fine grained microstructure; hysteresis loops; interaction domains; intrinsic coercivity; magnetic properties; magnetization reversal; nanocrystalline grains; network of grain boundaries; permanent magnets; strong pinning of walls; substitution effect; Amorphous materials; Annealing; Coercive force; Crystallization; Grain boundaries; Iron; Magnetic properties; Magnets; Temperature; Zirconium;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2002.803235

Filename

1042410