Discrepancy of room temperature ferromagnetism in Mo-doped In 2 O 3

Molybdenum-doped indium oxide nanopowders were synthesized via mechanical alloying with subsequent annealing at a relatively low temperature of 600 C. The morphologies and crystal structures of the synthesized nanopowders were examined by using scanning electron microscopy (SEM) and X-ray diffraction patterns. X-ray diffraction pattern of the milled mixture shows the presence of both In2O3 phase and Mo element. The presence of broad peaks in the pattern confirms that the synthesized powders are nanosized. The X-ray diffraction of annealed samples at 600 C shows the absence of Mo peaks revealing that the Mo was incorporated into the crystal lattices of In2O3. Interestingly, it was observed that the diffraction peaks were still broad in the annealed samples indicating the single phase at the nanoscale. From the XRD pattern, the calculated crystallite sizes were in the range of 12-18 nm. Magnetic properties of the synthesized Mo-doped In2O3 nanopowders were examined and it was found that the obtained nanopowders possess diamagnetic properties.