Spin dynamic effects on the resistivity and the magnetoresistance of a La1.85Sr0.15(Cu1-xLix)O-4 system with 0.0 <= x <= 0.15

The interplay between hole doping, spin fluctuations, and unusual normal-st ate properties in layered cuprates is relevant for the physics of high temp erature superconductors. For better understanding of the role of magnetic i nteractions on the conduction mechanism, a systematic study of the normal-s tate resistivity rho(x, T) of the La1.85Sr0.15(Cu1-xLix)O-4 system with 0.0 less than or equal to x less than or equal to 0.15 was performed down to 4 .2 K. A logarithmic contribution was found to properly describe the rho(x, T) deviation from linearity as T-c is approached. Scattering of the carrier s by spin fluctuations at the Cu-O-2 conduction planes is proposed to be th e source of the Kondo-like behavior. Negative magnetoresistance measurement s up to 8 T, with an increasing intensity with x, confirm the role of spin degrees in the resistivity behavior. (C) 1999 American Institute of Physics . [S0021-8979(99)37508-3].