The (SmZr)Co$_3$Phase in Sm(CoFeCuZr)$_rm z$Magnets

Detailed microstructural characterization of magnets and homogenized as-cast alloys, which included X-ray diffraction Rietveld analysis, has indicated that the so-called platelet or lamellae phase is (SmZr)
₁
(CoFeCu)
₃
with the PuNi
₃
structure and lattice parameters a~0.5 nm and c~2.4 nm. The structural and magnetic properties of the (SmZr)Co
₃
phase were investigated. The microstructure shows two phases differing in their Zr/Sm ratio. Magnetization curves for the samples (Sm
_0.33
Zr
_0.67
)Co
₃
, (Sm
_0.33
Zr
_0.67
)Co
_2.97
Fe
_0.03
, and (Sm
_0.67
Zr
_0.33
)Co
₃
are consistent with the two-phase microstructure observed. Room temperature coercivity values of these samples are low (ap1 kOe.)