Antiferromagnetism in EuPdGe₃

Highlights: • We show that EuPdGe₃ crystallizes in the BaNiSn₃-type structure with the lattice constants a = 4.4457(1) Å and c = 10.1703(2). • We demonstrate that EuPdGe₃ is an antiferromagnet with the Néel temperature T_N = 12.16(1) K. • The temperature dependence of the hyperfine magnetic field follows a S = 7/2 Brillouin function. • We find that the Debye temperature of the studied compound is 199(2) K. - Abstract: The results of X-ray diffraction, magnetic susceptibility and magnetization, and ¹⁵¹Eu Mössbauer spectroscopy measurements of polycrystalline EuPdGe₃ are reported. EuPdGe₃ crystallizes in the BaNiSn₃-type tetragonal structure (space group I4mm) with the lattice constants a=4.4457(1)Å and c=10.1703(2)Å. The results are consistent with EuPdGe₃ being an antiferromagnet with the Néel temperature T_N=12.16(1)K and with the Eu spins S=7/2 in the ab plane. The temperature dependence of the magnetic susceptibility above T_N follows the modified Curie-Weiss law with the effective magnetic moment of 7.82(1) μ_B per Eu atom and the paramagnetic Curie temperature of -5.3(1)K indicative of dominant antiferromagnetic interactions. The M(H) isotherms for temperatures approaching T_N from above are indicative of dynamical short-range antiferromagnetic ordering in the sample. The temperature dependence of the hyperfine magnetic field follows a S=7/2 Brillouin function. The principal component of the electric field gradient tensor is shown to increase with decreasing temperature and is well described by a T^3/2 power-law relation. The Debye temperature of EuPdGe₃ determined from the Mössbauer data is 199(2) K