The magnetic phases and structures of Ce(Ru1-xFex)2Ge2 studied by μ-SR

We report on the structures of the magnetic phases of CeRu2Ge2 and their evolution in the series Ce(Ru1-xFex)2Ge2. The crossover behavior between the ferromagnetic ground state of CeRu2Ge2 to the paramagnetic ground state of CeFe2Ge2 is compared to the behavior in the series CeRu2(Ge1-xSix)2. A profound difference is observed between these two series, which is in contradiction to the uniform behavior predicted by the Doniach-necklace model.