title: Physical properties of polycrystalline Sm₂PdGe₆ and Sm₂PtGe₆.
abstract: The compounds Sm₂TGe₆ (T = Pd, Pt,) were synthesized and characterized by x-ray diffraction, magnetization, electrical resistivity, thermoelectric power, and specific heat measurements performed in the temperature range 2-300 K. Additional resistivity and thermoelectric power measurements performed down to 0.35 K have not indicated superconductivity. These compounds crystallize in the orthorhombic structure of Ce₂NiGe₆ type and order antiferromagnetically at 23(1) and 30(1) K, respectively, showing localized magnetism of a Sm(3+) ion with a crystal field doublet level being the ground state. Below T(N), the electrical resistivity, the thermoelectric power, and the specific heat are dominated by electron-magnon scattering with an antiferromagnetic spin-wave spectrum typical of anisotropic antiferromagnetic systems. The thermoelectric power, S, achieves medium positive values at high temperatures, indicating a hole domination in electrical transport in both samples. At low temperatures, S changes its sign and becomes negative. At about 10 K a small negative maximum in S(T) occurs for both studied compounds. All the measurements carried out point to well-localized 4f-electrons in these two compounds, being strongly influenced by the crystal-electric-field effect with a significant admixture of two J-multiplets (5/2 and 7/2), typical for Sm-containing compounds.
authors.affiliation: W Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wrocław, Poland. R.Troc@int.pan.wroc.pl
authors.forename: R
authors.initials: R
authors.lastname: Troć
authors.forename: R
authors.initials: R
authors.lastname: Wawryk
authors.forename: K
authors.initials: K
authors.lastname: Gofryk
authors.forename: A V
authors.initials: AV
authors.lastname: Gribanov
authors.forename: Yu D
authors.initials: YD
authors.lastname: Seropegin