Kondo effect in 3d-host ferromagnetic Sm1−xCexMn2Ge2

Lattice, Ce L3-edge, magnetic susceptibility, and electrical resistivity results on polycrystalline Sm1−xCexMn2Ge2 (0 ≤ x ≤ 1) compound series are presented. The lattice parameters a and c increase almost linearly with the increase of Ce concentration x. The Ce-L3 X-ray absorption spectra indicate that the Ce in this series is nearly trivalent, and Ce valence decreases slightly with the increase of Ce concentration x. Magnetic susceptibility results indicate that the antiferromagnetic (AF) phase in the re-entrant ferromagnetic compound, SmMn2Ge2, is completely destroyed by merely 1.1% Ce for Sm substitution. For x > 0.011, only ferromagnetic (FM) phases exist below room temperature. It is found that in these materials Ce Kondo scattering coexists with the 3d-host FM fields and is also effectively weakened by such fields.