Influence of ball milling on structure and magnetotransport of chromium dioxide granules

The influence of ball milling on the structure and magnetotransport of chromium dioxide granules was studied. A lattice expansion was found to occur during the process which led to a decrease in the specific magnetization. The low field magnetoresistance (MR) was also found to decrease with an increase in the milling time, which was due to the lattice expansion and the reduction of spin polarization of CrO2. The analysis showed that the grain size affected the resistivity, which was due to the increase of specific surface area, and changes to the surface nature of CrO2 grains.