Surface segregation and restructuring of colossal-magnetoresistant manganese perovskites La_0.65Sr_0.35MnO₃

Authors

Hani Dulli, University of Tennessee, KnoxvilleFollow
Peter A. Dowben, University of Nebraska-LincolnFollow
Sy-Hwang Liou, University of Nebraska-LincolnFollow
E. Ward Plummer, University of Tennessee, KnoxvilleFollow

Date of this Version

12-1-2000

Comments

Published in Physical Review B: Condensed Matter and Materials Physics 62, R14629 (2000). Copyright 2000 The American Physical Society. Used by permission.
URL: http://link.aps.org/abstract/PRB/v62/pR14629
DOI: 10.1103/PhysRevB.62.R14629

Abstract

We have investigated the surface chemical composition of crystalline films of La_0.65Sr_0.35MnO₃ by angle-resolved x-ray photoelectron spectroscopy. The surface composition was found to be significantly different from that of the bulk because of an appreciable Sr segregation. Furthermore, our study suggests that this Sr segregation has caused a major restructuring of the surface region characterized by the formation of a Ruddlesden-Popper phase (La,Sr)_n+1Mn_nO_3n+1 with n = 1. Segregation and restructuring in the surface region should be common in these doped perovskites and will have a profound impact on the electronic and magnetic properties of ultrathin films and magnetic tunneling junctions made of these materials.