Microstructure and properties of Si-TaSi₂ eutectic in situ composite for field emission

The Si-TaSi₂ eutectic in situ composite for field emission is prepared by electron beam floating zone melting (EBFZM) technique on the basis of Czochralski (CZ) crystal growth technique. The directional solidification microstructure and the field emission properties of the Si-TaSi₂ eutectic in situ composite prepared by two kinds of crystal growth techniques have been systematically tested and compared. Researches demonstrated that the solidification microstructure of EBFZM can be fined obviously because of the relatively high solidification rate and very high temperature gradient, i.e. both the diameter and inter-rod spacing of the TaSi₂ fibers prepared by EBFZM technique were decreased, and the density and the volume fraction of the TaSi₂ fibers prepared by EBFZM technique were increased in comparison with that of the TaSi₂ fibers prepared by CZ method. Therefore the field emission property of the Si-TaSi₂ eutectic in situ composite prepared by EBFZM can be improved greatly, which exhibits better field emission uniformity and straighter F-N curve.