2002/04/09 by T. Fujii, I. Terasaki, Ichiro Terasaki +4 · 1 citation
Materials Science · Physics and Astronomy · #Advanced Thermoelectric Materials and Devices #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1016/s0921-4534(02)01407-7
4pages 5 figures, Proceedings of ISS2001, Physica C (in press)
arxiv created 2002/04/09 · openalex publication_date 2002/10/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We investigated the in-plane anisotropy on the resistivity and thermopower of the Bi2Sr2CaCu2O8+δ (Bi-2212) and Bi-Sr-Co-O (BiCo) single crystals. In Bi-2212, the b-axis resistivity is higher than the a-axis resistivity, and is expressed as a sum of the a-axis resistivity and an additional residual resistivity. A downward deviation due to pseudogap is observed below a characteristic temperature T^*, which is isotropic in the form of conductivity. These results suggest that the modulation structure along the b-axis works as an anisotropic scattering center, but does not affect the pseudogap formation. On the other hand, the anisotropy of the resistivity and the thermopower in Pb-doped BiCo is substantial, probably owing to the misfit structure between the hexagonal CoO2 layer and the rock salt Bi2O2 layer. However, the anisotropy in the resistivity in Pb-free BiCo is very small, suggesting that the in-plane anisotropy is averaged by the modulation structure, whose direction is tilted by 45 deg from the a- and b-axes.