Transport properties of the single-crystal La2−xBaxCuO4 (0≤x≤0.11)

We report on the temperature dependence of the in-plane electrical resistivity ρab and the in-plane Hall coefficient RH in various magnetic fields of the single-crystal La2−xBaxCuO4 with x=0.083 and 0.11. In x=0.11, which is close to x=1/8, where the superconductivity is strongly suppressed, a clear jump in ρab and a drop in RH have been observed at Td2∼53 K, where the structural phase transition between the orthorhombic mid-temperature and tetragonal low-temperature phases occurs. Moreover, a sign reversal of RH has been observed below ∼25 K and the magnitude of the sign reversal increases with increasing magnetic field. In x=0.083, on the other hand, there is neither jump in ρab nor drop in RH at Td2, and also no sign reversal in RH at low temperatures even in magnetic fields up to 9 T. In conclusion, there is no doubt that a static stripe order of holes and spins, observed in La1.6−xNd0.4SrxCuO4 with x∼1/8, is formed below Td2 also in La2−xBaxCuO4 with x∼1/8. The RH in the stripe-ordered state has a negative value, which is consistent with the recent theory by Prelovšek et al.