Transport and magnetic properties of RERuSn3 (RE=La, Ce, Pr, Nd and Sm) RERuSn3(RE:La,Ce,Pr,Nd,Sm)の輸送現象及び磁性

博士論文

The electrical resistivity, thermoelectric power, Hall effect, magnetoresistivity, magnetic susceptibility, magnetization and specific heat on intermetallic ternary compounds RERuSn, (RE=La, Ce, Pr, Nd and Sm) have been investigated. CeRuSn_3 is found to be a new heavy fermion compound with a large coefficient of electronic specific heat γ=400 mJ/mol .K^2 at OK. In order to gain the deeper insight into the heavy fermion state of CeRuSn_3, non-stoichiometric compounds CeRuSn_x (2.85_<≦x≦>3.15), CeRu(Sn_<1-y> Tn_y,) _3 and NdRuSn_<2.91> have also been investigated. The low temperature resistivity for CeRuSn_x shows a maximum at x=3.O as a function of x. Sn deficjent samples show three step phase transitions at 33K, 4K and 1.3K. SmRuSn_3 is a new valence fluctuating compound with an antiferromagnetic ordering at 6K. The valeney of Sm ion is estimated to be 2.8～2.9.　Both　CeRuSn_3 and SmRuSn_3 show unique magnetic features possibly due to their crystal structures as compared to the reported heavy fermion and the valence fluctuation compounds. LaRuSn_3 shows superconducting transition at 1.5K. PrRuSn_3 and NdRuSn_3 do not show any magnetic ordering down to 1.8K.

東京都立大学, 1991-03-25, 理学博士, 甲第263号