Abstract

The dc resistivity, magnetoresistance and magnetic susceptibility of La Sr CoO compounds have been investigated in the temperature range of 4K to 300K for magnetic fields up to 7 T. In the doping range studied (0.05 0.25) the electronic properties of the material exhibit a crossover from semiconducting to metallic behavior. The magnetoresistance is highest in the semiconducting state. A correlation was found between the energy gap determined from the dc conductivity and the energy scale identified from neutron scattering data. The results are interpreted in terms of a double exchange model.