In-plane Conduction and c-axis Polarization in the Misfit-layered Oxide [Bi_2Ca_2O_4]_qCoO_2

摘要

We have used low-frequency dielectric measurements to study the evolution of anisotropic charge transport in misfit layered oxides [Bi_2Ca_2O_4]_qCoO_2. Above ～60 K, the in-plane dc conductivity obeys the Arrhenius law and the dielectric polarization occurs along the c direction. We point out that this c-axis polarization is attributed to the activated carrier which is confined to ab plane.