Shirakawa Naoki

Novel Hall-Coefficient Behavior inSuperconducting Sr2RuO4

We present the temperature dependence of the Hall coefficient ( R H ) of Sr 2 RuO 4 , in which superconductivity with T c =0.93 K has been discovered recently. The value of R H shows strong temperature dependence, and sign reversal occurs at around 20 K, i.e., R H is positive and small (≤2×10 -11 m 3 C -1 ) for T >20 K, while for T <20 K R H is negative and | R H | continuously increases at least down to 1.8 K, where R H =-1.37×10 -10 m 3 C -1 . A possible mechanism of the temperature dependence of R H , involving the electron-correlation effect, is discussed.

Orbital-Degenerate Paramagnetic Metal Sr 2MoO 4: An Electronic Analogue to Sr 2RuO 4

We present the first systematic study on polycrystalline Sr 2 MoO 4 as an electronic analogue to the spin-triplet superconductor Sr 2 RuO 4 . The Pauli paramagnetic susceptibility and metallic beha...We present the first systematic study on polycrystalline Sr 2 MoO 4 as an electronic analogue to the spin-triplet superconductor Sr 2 RuO 4 . The Pauli paramagnetic susceptibility and metallic behaviors of specific heat and electrical resistivity have been observed. The density of states at the Fermi level D(E F ) deduced from the results is about three times smaller than that of Sr 2 RuO 4 . Any indication of superconductivity intrinsic to Sr 2 MoO 4 has not been observed down to 25 mK, which may correspond to the smaller D(E F ). We discuss the origin of the difference in electronic states between Sr 2 MoO 4 and Sr 2 RuO 4 .We present the first systematic study on polycrystalline Sr 2 MoO 4 as an electronic analogue to the spin-triplet superconductor Sr 2 RuO 4 . The Pauli paramagnetic susceptibility and metallic behaviors of specific heat and electrical resistivity have been observed. The density of states at the Fermi level D ( E F ) deduced from the results is about three times smaller than that of Sr 2 RuO 4 . Any indication of superconductivity intrinsic to Sr 2 MoO 4 has not been observed down to 25 mK, which may correspond to the smaller D ( E F ). We discuss the origin of the difference in electronic states between Sr 2 MoO 4 and Sr 2 RuO 4 .