Spin blockade effects in chromium oxide intergrain magnetoresistance

Authors

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
Ruihua Cheng, University of Nebraska-Lincoln
B. Xu, University of Nebraska-Lincoln
C.N. Borca, University of Nebraska-Lincoln
Peter A. Dowben, University of Nebraska-LincolnFollow
Bernard Doudin, University of Nebraska-LincolnFollow

Date of this Version

5-15-2002

Comments

Published Journal of Applied Physics 91 (2002) 8801-8803. Permission to use.

Abstract

CrO₂ thin films with crystallites of a significant size permit investigation of the thin intergrain conduction between a limited numbers of crystals. Phoemission techniques reveal that the CrO₂ films are covered by a 1–2-nm-thick Cr₂O₃ insulating barrier. The electronic band gap of the surface electrons is 3.4 eV at low temperatures, decreases sharply down to 2.8 eV at ambient. Electric transport though a few junctions in series shows a remarkable zero-bias anomaly, interpreted in terms of blockade effects. We show that the magnetoresistance is governed by low-bias blockade in these junctions. © 2002 American Institute of Physics. [DOI: 10.1063/1.1452240]