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

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

PHYSICA C - SUPERCONDUTIVITY

ELSEVIER SCIENCE BV

Lugar: New York; Año: 1993 vol. 227 p. 237 - 244

0921-4534

We have measured the electrical resistivity (T) of the chlorinated La2-xSrxCuO4-δ high-Tc superconductor, in a wide range of temperatures (40 ≤ T ≤ 800 K). The systematic effects in (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.