Impedance and specific heat of RM 4 Al 8 and RAg 6 In 6 compounds

The results of experimental investigations of the temperature dependences of the surface resistance and specific heat of ternary rare-earth compounds are presented: LuFe 4 Al 8 , ScFe 4 Al 8 , CeFe 4 Al 8 , CeCr 4 Al 8 , YFe 4 Al 8 , YCr 4 Al 8 , YMn 4 Al 8 , UCu 4 Al 8 , LaAg 6 In 6 , and PrAg 6 In 6 , which have ThMn 12 structure. It is shown that at a certain temperature, characteristic for each compound with Fe, Cr, and Mn, below the Néel temperature a jump is observed in the total impedance and specific heat. At lower temperatures a negative magnetoresistance is observed in these compounds in weak magnetic fields. Superconducting phases are found in the compounds ScFe 4 Al 8 (T c =6 K ), YCr 4 Al 8 (T c =4.5 K ), YFe 4 Al 8 (T c =6 K ), and PrAg 6 In 6 (T c =8.3 K ).