Structure and transport properties of Cr doped La214 system

The structure and normal state transport properties of La1.85-xSr0.15+xCu1- xCrxO4 (0 less than or equal to x less than or equal to 0.30) have been inv estigated by means of XRD, resistivity and thermoelectric power. The analys is of experimental results indicates that Cr doping introduces disorder int o the system, which causes an obvious metal-insulator (MI) transition in th e samples with high doping level. This MI transition can be well interprete d in the context of the Anderson theory of disorder-induced localization. I n addition, Cr doping leads to the broad peaks in the S-T curves shifting u p to high temperature, which is in contrast to that of the non-magnetic ele ment, Al, doped system. This discrepancy is analyzed in terms of the change s of d-p hybridization and spin correlation. (C) 1999 Elsevier Science B.V. All rights reserved.