Transport and magnetic properties of RERuSn₃(RE=La, Ce, Pr, Nd, Sm): a heavy fermion compound CeRuSn₃and a new valence fluctuating compound SmRuSn₃

Abstract

The electrical resistivity, thermoelectric power, Hall effect, magnetoresistivity, magnetic susceptibility and magnetization of intermetallic ternary compounds RERuSn3 (RE=La, Ce, Pr, Nd and Sm), CeRuSnx (2.85<or=x<or=3.15), CeRu(Sn1-yIny)3 and NdRuSn2.91 have been measured. CeRuSn3 was reported to be a heavy fermion compound with an enormous coefficient of electronic specific heat gamma =1.67 J K-2/mole at 0.6 K. In order to gain a deeper insight into the heavy fermion state of CeRuSn3, nonstoichiometric compounds CeRuSnx (2.85<or=x<or=3.15) have also been investigated. The low temperature resistivity shows a maximum at x=3.0 as a function of x. Sn deficient samples show three step phase transitions at 33 K, 4 K and 1.3 K. PrRuSn3 and NdRuSn3 do not show any magnetic ordering down to 1.8 K. SmRuSn3 is a new valence fluctuating compound with an antiferromagnetic ordering at 6 K.