Nonlinear current-voltage characteristics of oxygen-deficient La$_{0.67}$Ca$_{0.33}$MnO$_{3-y}$ films

POSTER

Abstract

Two different types of nonlinear current-voltage characteristics are observed in oxygen-deficient La$_{0.67}$Ca$_{0.33}$MnO$_{3-y}$ (LCMO) films at temperatures below insulator-metal transition. The parabolic-like dynamic conductance $G(V)$, defined as d$I$/d$V$, curves near zero bias observed in highly oxygen-deficient LCMO films implies the contribution from the spin-dependent tunneling transport between ferromagnetic clusters with magnetic-disordered regions serving as tunneling barriers. On the other hand, for the slightly oxygen-deficient LCMO films, dips around zero bias were observed in nonlinear $G(V)$ curves and have been attributed to spin-flip scattering with oxygen vacancies serving as scattering centers.

*Supported by the National Science Council of Taiwan, under Grant No. NSC 95-2112-M-131-002-MY3

Authors

  • Shiu-jen Liu

    • Department of Materials Engineering, Mingchi University of Technology

  • J.Y. Juang

    • Department of Electrophysics, National Chiao Tung University

  • J.-Y. Lin

    • Institute of Physics, National Chiao Tung University

  • K.H. Wu

    • Department of Electrophysics, National Chiao Tung University

  • T.M. Uen

    • Department of Electrophysics, National Chiao Tung University

  • Y.S. Gou

    • Department of Physics, National Taiwan Normal University