ELECTRICAL-CONDUCTIVITY IN LA1-XSRXMNO3+DELTA

The electrical conductivity of La1-xSrxMnO3+delta is found to depend o n temperature, density and microstructure, and chemical composition. A one dimensional model is used to describe the small polaron hopping c onductivity qualitatively. The relation between conductivity and densi ty obeys the Bruggeman theory and it is shown that differences in micr ostructure can strongly influence the conductivity. At 1220 K the elec trical conductivity of dense La1-xSrxMnO3+delta increases with x from 115 S.cm-1 for x=0 to 300 S.cm-1 for x=0.50. The oxygen content delta seems to be of no influence. The latter is explained by defect chemica l considerations.