Extrinsic and intrinsic magnetoresistance contributions of CrO2 thin films

Abstract

The growth of (010)-oriented CrO2 thin films on Al2O3(0001) substrates leads to a higher grain boundary density than the growth of (100)-oriented CrO2 thin films on isostructural TiO2(100) substrates. For both types of films an intrinsic linear contribution to the high field magnetoresistance (MR) due to spin disorder has been determined at T=300 K. This contribution does not depend on the crystalline quality of the films and supports the suggested intrinsic double exchange mechanism for CrO2. At low temperature (T=10 K) intergrain tunneling MR and Lorentz MR appear, which strongly depend on the crystalline properties of the CrO2 films.