Antiferromagnetism in EuPdGe3

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 TN=12.16(1)K and with the Eu spins S=7/2 in the ab plane. The temperature dependence of the magnetic susceptibility above TN follows the modified Curie-Weiss law with the effective magnetic moment of 7.82(1) μB 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 TN 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 T3/2 power-law relation. The Debye temperature of EuPdGe3 determined from the Mössbauer data is 199(2)K.