Quasi-Two-Dimensional Fermi-Liquid State in Sr2RhO4-δ

Abstract

Single crystals of layered perovskite Sr 2 RhO 4-δ (δ=0.0 and 0.1) are successfully grown by the floating-zone method. Stoichiometric single crystals (Sr 2 RhO 4.0 ) are obtained by O 2 -annealing the as-grown crystals (Sr 2 RhO 3.9 ). Sr 2 RhO 4.0 and Sr 2 RhO 3.9 show quasi-two-dimensional Fermi-liquid behavior at low temperatures, whereas there are large differences in the anisotropy of electrical resistivity ρ c (3 K)/ρ a b (3 K) and Wilson ratio R w between Sr 2 RhO 4.0 and Sr 2 RhO 3.9 : ρ c (3 K)/ρ a b (3 K) = 2400 (19000) and R w =3.8 (6.4) for Sr 2 RhO 4.0 (Sr 2 RhO 3.9 ). The differences observed between the temperature dependence of the in-plane electrical resistivity ( T <15 K), magnetic susceptibility ( T <300 K) and specific heat ( T <10 K) of Sr 2 RhO 4.0 and Sr 2 RhO 3.9 are mainly derived from those between the density of states and band structure near the corresponding Fermi level. This indicates that the changes in these physical properties, which are accompanied by oxygen defects in th...