  Effect of Ti doping on the electrical transport and magnetic properties of
layered Na0.8Co1-xTixO2 compounds has been investigated. The lattice parameters
a and c increase with x. A minor amount of Ti doping results in a
metal-insulator transition at low temperatures. For samples with x > 0.03, the
variable-range hopping process dominates the transport behavior above a certain
temperature. The temperature dependence of magnetization of all the samples is
found to obey the Curie-Weiss law. The mechanism of the doping effect is
discussed.
