Title :
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
fDate :
9/1/2002 12:00:00 AM
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 SmCo6.4 Zr0.2Ti0.4 and SmCo6.4Fe0.1Zr0.1Ti0.4. The high coercivity of the ball-milled SmCo7-xTix 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;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2002.803235
