Preparation and magnetoresistance of thin CrO2 films

Highly textured chromium dioxide (CrO(2)) films have been deposited on Al(2)O(3) single-crystal substrates by atmospheric pressure chemical vapor deposition method (CVD). X-ray diffraction patterns show that the CrO(2) films are (100)-oriented on Al(2)O(3) (001) substrates, and are (101)-oriented on Al(2)O(3) (012) substrates. Scanning electron microscopy images indicate that the (100)-oriented CrO(2) films grown on Al(2)O(3) (001) substrates have smoother surface and better qualities than that grown on Al(2)O(3) (012) substrate. At room temperature, the magnetoresistance of the (100)- and (101)-oriented CrO(2) films are nearly same, and both show a linear dependence on applied magnetic field. While at 80 K, the (101)-oriented CrO(2) films show a much larger magnetoresistance compared with the (100)-oriented CrO(2) films. The reasons are briefly discussed. (C) 2008 Elsevier B.V. All rights reserved.