Preparation and magnetoresistance of submicron CrO2 thin film on poly-crystal SnO2 film

Abtract The submicron chromium dioxide (CrO 2 ) thin films have been fabricated on poly-crystal stannic oxide (SnO 2 ) films by atmospheric pressure chemical vapor deposition method. At low temperature, the CrO 2 thin film has sharp increase in the MR at low fields. This should be mainly attributed to spin-dependent tunneling through grain boundaries between adjacent CrO 2 grains. At high temperature, the magnetoresistance (MR) of CrO 2 thin film has small value and shows linear dependence on applied magnetic field. The resistivity of CrO 2 thin film decreases significantly as temperature increases, which can be best described by the fluctuation-induced tunneling model below 220 K. The MR for the CrO 2 thin film on SnO 2 film also decreases rapidly with increasing temperature.