Nanostructured titanium disilicide powders: Preparation by self-propagating high-temperature synthesis and mechanochemical processes and physicochemical properties

Nanostructured titanium disilicide (TiSi2) powders with semiconducting properties have been prepared via cold fusion of silicon and titanium nanopowders and mechanochemical activation of TiSi2 powders prepared by self-propagating high-temperature synthesis. The semiconducting properties of TiSi2 have been shown to be determined by the nanocrystallite size. Basic to the formation of TiSi2 as a semiconductor material is a change in its band structure upon the conversion of the conductor to a semiconductor. The transformation takes place when the crystallite size decreases from microns to the nanometer range (≤70 nm). Such crystallites are nanoclusters with distorted order in the arrangement of the silicon and titanium atoms.