Microstructure And Property Of Si-TaSi₂ Eutectic In Situ Composite For Field Emission

Nowadays the research of field emission display materials is mostly focused on semiconductor Si , diamond film , carbon nanotubes and so on. Si-TaSi2 eutectic in situ composite for field emission is one of the Semiconductor Metal Eutectic materials(SME), which has so many characters such as the relatively low work function, good electricity conduction, Schottky junctions grown spontaneously into the matrix etc, and it is regarded as one of the excellent field emission materials . In this paper, the directionally solidified Si-TaSi2 eutectic in situ composite for field emission is prepared with the electron beam floating zone melting (EBFZM) technique. Microstructure of directionally solidified Si-TaSi2 eutectic in situ composite and the characters of field emission are investigated by the help of metallograph, electron micrograph, imagine management technology and other analysis test methods.Microstructure of directionally solidified Si-TaSi2 eutectic in situ composite is investigated at the different solidification rates. Microstructure is obviously thinned as the solidification rate increases. With the increasing of the solidification rate, the diameter and the inter-fiber spacing of the TaSi2 fibers decrease, while the fiber density and the volume fraction increase. The phases composition of the eutectic is investigated by the help of spectrum. Precinct electronic diffraction is manipulated on the transmission electron micrograph, which demonstrates that the locationrelationship between Si matrix and TaSi2 fibers is [011]Si//[0001]TaSi2,(022)Si//(0120)TaSi2. The evolvement principle of solid/liquid interface is obtainedas the solid/liquid interface is fixed during solidification process by the method of zero power. With the increasing of the solidification rate, solid/liquid interface changes from planar interface to cell interface then transits to planar interface again. Intergrowth dynamics of facet/non-facet and transformation mechanism of TaSi2 phase are investigated as well.Facture technique of Si matrix cone-shaped field emission array is explored according to optional corrode theory, and field emission property of the samples is tested at the same time. So the relationship among materials' property,microstructure and technical parameters is confirmed primarily.