Ferromagnetic ordering in ThSi2 type CeAu0.28Ge1.72

The compound CeAu0.28Ge1.72 crystallizes in the ThSi2 structure type in the tetragonal space group I41/amd with lattice parameters a=b=4.2415(6) Å c=14.640(3) Å. CeAu0.28Ge1.72 is a polar intermetallic compound having a three-dimensional Ge/Au polyanion sub-network filled with Ce atoms. The magnetic susceptibility data show Curie–Weiss law behavior above 50 K. The compound orders ferromagnetically at ∼8 K with estimated magnetic moment of 2.48 μB/Ce. The ferromagnetic ordering is confirmed by the heat capacity data which show a rise at ∼8 K. The electronic specific heat coefficient (γ) value obtained from the paramagnetic temperature range 15–25 K is∼124(5) mJ/ mol K2. The entropy change due to the ferromagnetic transition is ∼4.2 J/mol K which is appreciably reduced compared to the value of R ln(2) expected for a crystal-field-split doublet ground state and/or Kondo exchange interactions.