Affordable Access

Transport properties and spin correlations of La<sub>1</sub><sub>.</sub><sub>8</sub><sub>5</sub><sub>-</sub><sub>x</sub>Sr<sub>0</sub><sub>.</sub><sub>1</sub><sub>5</sub><sub>+</sub><sub>x</sub>Cu<sub>1</sub><sub>-</sub><sub>x</sub>Fe<sub>x</sub>O<sub>4</sub>

American Physical Society
Publication Date
  • 5-I Nano


A series of double-doped La1.85-xSr0.15+xCu1-xFexO4 (0less than or equal toxless than or equal to1) ceramic samples were prepared by the solid-state reaction method. The structure, transport properties, and spin correlations were studied by means of x-ray diffraction, resistivity, thermoelectric power (TEP) and electron spin resonance (ESR). Double doping causes an increase of the lattice parameter a and a decrease of c. A great discrepancy of the thermal activation energy is derived from the resistivity and TEP at high doping levels, which can be understood in terms of a polaron model. The ESR result indicates that the double doping influences the spin correlation of the CuO2 plane markedly, which suggests that the Fe3+ spins change from localization to delocalization as x increases from low doping to high doping. A close relation between localized spin scattering and the broad peak in the TEP versus T curve is proposed. A comparison of the transport mechanism between the Fe doped and the Co and Ni doped La214 systems is given in this paper.

There are no comments yet on this publication. Be the first to share your thoughts.