Characterization of the native Cr₂O₃ oxide surface of CrO₂

Authors

Ruihua Cheng, University of Nebraska-Lincoln
B. Xu, University of Nebraska-Lincoln
C.N. Borca, University of Nebraska-Lincoln
Andrei Sokolov, University of Nebraska-LincolnFollow
C.S. Yang, University of Nebraska-Lincoln
Lu Yuan, University of Nebraska-LincolnFollow
Sy_Hwang Liou, University of Nebraska-LincolnFollow
Bernard Doudin, University of Nebraska-LincolnFollow
Peter A. Dowben, University of Nebraska-LincolnFollow

Date of this Version

11-5-2001

Comments

Published Applied Physics Letters 79 (2001) 3122-3124. Permission to use.

Abstract

Using photoemission and inverse photoemission, we have been able to characterize the Cr₂O₃ oxide surface of CrO₂ thin films. The Cr₂O₃ surface oxide exhibits a band gap of about 3 eV, although the bulk CrO₂ is conducting. The thickness of this insulating Cr₂O₃ layer is twice the photoelectron escape depth which is about 2 nm thick. The effective Cr₂O₃ surface layer Debye temperature, describing motion normal to the surface, is about 370 K. From a comparison of CrO₂ films grown by different techniques, with different Cr₂O₃ content, evidence is provided that the CrO₂ may polarize the Cr₂O₃. © 2001 American Institute of Physics. [DOI: 10.1063/1.1416474]