Electronic-structure modifications induced by surface segregation in La_0.65Pb_0.35MnO₃ thin films

Authors

C.N. Borca, University of Nebraska-Lincoln
B. Xu, University of Nebraska-Lincoln
T. Komesu, University of Nebraska-LincolnFollow
H.-K. Jeong, University of Nebraska-LincolnFollow
M.T. Liu, University of Nebraska-Lincoln
Sy_Hwang Liou, University of Nebraska-LincolnFollow
Shane Stadler, Material Physics Branch, Naval Research Laboratory - Washington DCFollow
Y. Idzerda, Material Physics Branch, Naval Research Laboratory - Washington DC
Peter A. Dowben, University of Nebraska-LincolnFollow

Date of this Version

12-1-2002

Comments

Published by EDP Sciences; Europhysics Letters 56 (2001) 722-728. Copyright 2001. Permission to use.

Abstract

Using spin-polarized inverse photoemission and X-ray absorption spectroscopy techniques, we show that the electronic structure of La_0.65Pb_0.35MnO₃ thin films depends on the composition at the surface. With a gentle annealing procedure, the surface provides a maximum of 80% spin asymmetry at 0.5 eV above the Fermi level in spite of extensive Pb segregation. A heavily annealed (restructured) surface exhibits a reduced surface "ordering" temperature of 240 K (compared to the approximately 335 K bulk value) as well as a reduced spin asymmetry value of 40% at 0.5 eV above Fermi energy.