Chlorination effects in electrical transport properties of ceramic La2-xSrxCuO4-δ-yCly

ACHA, C; BEKERIS, V; URBA, L; POLLA, G; LEVY, P; LEYVA, G; DE BENYACAR, M.A.R; DE LA CRUZ, F

PHYSICA C - SUPERCONDUTIVITY

ELSEVIER SCIENCE BV

Año: 1994 vol. 227 p. 237 - 244

0921-4534

We have measured the electrical resistivity ρ{variant}(T) of the chlorinated La2-xSrxCuO4-δ high-Tc superconductor, in a wide range of temperatures (40 ≤ T ≤ 800 K). The systematic effects in ρ{variant}(T) of Cl and Sr contents allowed us, within the Drude and VRH models, to determine the role played by Cl in electrical transport properties: carrier concentration decreases linearly with increasing Cl concentration, and Cl also modifies the electron localized low temperature conducting regime, increasing disorder for low Sr concentration (x = 0.065) while ordering the system for high Sr concentrations (0.08 ≤ x ≤ 0.2). Changes in lattice parameters indicate different structural site occupancies for Cl, depending on Sr doping: for low Sr concentrations an expansion in the c-crystallographic axis with increasing Cl content is observed, while a contraction results for higher Sr contents. © 1994.