Dependence of the Structures of Manganese Dioxides on Their Chemical Properties

Anisotropic temperature dependence of the electrical resistivity in LiCoO2 has been first clarified using chemically and structurally characterized single crystal specimens. The resistivities both perpendicular and parallel to the c-axis show semiconductive behavior with large anisotropy of rhoc/rhoa~500 at 300 K. The temperature dependence of inplane resistivity suggested a variable range hopping in the two-dimensional system.