Crystal Structure and Magnetism of Noncentrosymmetric Eu2Pd2Sn

The new intermetallic compound Eu2Pd2Sn has been investigated. A single crystal was selected from the alloy and was analyzed by single-crystal X-ray diffraction, revealing that this compound possesses the noncentrosymmetric Ca2Pd2Ge structure type being, so far, the only rare-earth-based representative. Bonding analysis, performed on the basis of DOS and (I)COHP, reveals the presence of strong covalent Sn-Pd bonds in addition to linear and equidistant Pd-Pd chains. The incomplete ionization of Eu leads to its participation in weaker covalent interactions. The magnetic effective moment, extracted from the magnetic susceptibility chi(T) is mu(e)(ff) = 7.87 mu(B), close to the free ion Eu2+ value (mu(eff) = 7.94 mu(B)). The maximum of chi(T) at T-N similar to 13 K indicates an antiferromagnetic behavior below this temperature. A coincident sharp anomaly in the specific heat C-P(T) emerges from a broad anomaly centered at around 10 K. From the reduced jump in the heat capacity at T-N a scenario of a transition to an incommensurate antiferromagnetic phase below T-N followed by a commensurate configuration below 10 K is suggested.