Resistivity anomaly in the vicinity of a structural phase transition in La1-xSrxMnO3 - art. no. 180405

The resistivity rho has been measured up to 900 K in La1-xSrxMnO3 (0 less t han or equal to x less than or equal to 0.15) single crystals to investigat e the nature of charge transport phenomena both above and below the coopera tive Jahn-Teller orbital-ordering temperature (T-JT). At high temperatures above T-JT, rho is almost temperature independent for LaMnO3 whereas rho ex hibits a strong temperature dependence for x > 0 samples, In the orbitally ordered state, rho can be described well by a small-polaron hopping model w ith rho (T) = rho (0) exp(E-rho/kT). We observe that both above and below T JT the resistivity can be fitted with the same activation energy E-rho but with different prefactor rho (0) for x > 0 samples. Though rho decreases mo notonically with increasing doping concentration, E-rho is almost independe nt of Sr concentration up to x = 0.10 and then decreases rapidly above this value of x.