Magnetotransport properties of CrO₂ films down to single-grain sizes

Authors

Lu Yuan, Physics Department, University of NebraskaFollow
Y. Ovchenkov, University of Nebraska - Lincoln
Andrei Sokolov, University of Nebraska-LincolnFollow
C.-S. Yang, University of Nebraska - Lincoln
Bernard Doudin, University of Nebraska-LincolnFollow
Sy_Hwang Liou, University of Nebraska-LincolnFollow

Date of this Version

5-15-2003

Comments

Published by American Institute of Physics. J. Appl. Phys., 93, 6850 (2003). ©2003 American Institute of Physics. Permission to use. http://jap.aip.org/jap/.

Abstract

The magnetotransport properties of CrO₂ films down to single-grain sizes have been investigated. The magnetoresistance of highly grain oriented CrO₂ (100) films, deposited onto TiO₂ (100) substrates using a high pressure cell, has been measured in the temperature range of 1.5–300 K and in magnetic fields up to 6 T. The difference in the magnetoresistance at the low temperature of these samples is related to the value of the residual resistance ratio (RRR = R_{273 K}/R_{4.2 K}) of the samples. The negative magnetoresistance observed in some of these films is likely due to defects (disorder) in the CrO₂ crystal. We observed a large positive longitudinal magnetoresistance in the CrO₂ sample when it was measured with the current perpendicular to thec axis. The nature of the large value of the longitudinal magnetoresistance may be related to the complex configuration of the Fermi surface of CrO₂.