Niobium silicide

Niobium silicide (NbSi3) is deposited by the silane reaction with niobium chloride. It has an A15 structure and is a superconductor. 

The nozzle of original design was fabricated from a niobium alloy coated with niobium silicide and could not operate above 1320°C. This was replaced by a thin shell of rhenium protected on the inside by a thin layer of iridium. The iridium was deposited first on a disposable mandrel, from iridium acetylacetonate (pentadionate) (see Ch. 6). The rhenium was then deposited over the iridium by hydrogen reduction of the chloride. The mandrel was then chemically removed. Iridium has a high melting point (2410°C) and provides good corrosion protection for the rhenium. The nozzle was tested at 2000°C and survived 400 cycles in a high oxidizer to fuel ratio with no measurable corrosion.O l... 

Field emission displays are VFDs that use field emission cathodes as the electron source. The cathodes can be molybdenum microtips,33-35 carbon films,36,37 carbon nanotubes,38" 16 diamond tips,47 or other nanoscale-emitting materials.48 Niobium silicide applied as a protective layer on silicon tip field emission arrays has been claimed to improve the emission efficiency and stability.49 ZnO Zn is used in monochrome field emission device (FED) displays but its disadvantage is that it saturates at over 200 V.29... 

Niobium silicide (NbSi ) is used as a lining for high-temperature refractory furnaces. 

Niobium diselenide (NbSc2) is sometimes used as a lubricant at high temperatures. It does not break down at temperatures up to about 2372°F (1300°C). Niobium silicide (NbSi2) is used as a refractory material. A refractory material is one that can withstand very high temperatures. 

Iodine is also helpful in forming niobium silicide from Nb and Si02 ... 

The Sc-Nb Si isothermal section at 800"C presented in fig. 61 has been reported by Kotur (1986). Solid solution of substitution Sc5 1.5Nbo-3.5Si3 occurs in the system. The variation of the lattice parameters show negative deviation from Vegard s rule. Other binary scandium and niobium silicides do not dissolve the third component. T vo ternary compounds exist in the system. Probably Sco.4Nb4.6Si3 is a solid solution of the binary... 

Oxidation of niobium silicide-based in-situ composites... 

B.P. Bewlay, M.R. Jackson and M.F.X. Gighotti, Niobium silicide high temperature in situ composites, in Intermetallic Compounds Vol. 3, Principles and Practice, J.H. Westbrook and R.L. Fleischer (eds), John Wiley Sons, 2002, p. 541. 

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