Electric transport in R2MGe6 ternary compounds (R = La, Ce, Gd, Tb, Dy, Ho; M = Mn, Ni, Cu)

Polycrystalline samples of the intermetallic compounds La2MnGe6, Ce2MnGe6, La2CuGe6, Ce2CuGe6, and R2NiGe6 (R = Gd, Tb, Dy, Ho), which belong to the Ce2CuGe6 type of structure (Amm2 or Cm2m space group), were studied by means of the electrical resistivity and differential thermopower measurements. They exhibit the metallic-like behavior in the temperature range from 5 to 290 K. The peculiarities in both resistivity and thermopower temperature dependencies correlate with corresponding magnetic transition Ttr temperatures.