Tungsten disilicide

Tungsten disilicide (WSi2) is refractory and stable with low resistivity. As with other silicides, a common deposition system uses silane as the silicon source with tungsten hexafluoride as follows  

Thi s reaction is usually carried out at 3 50°C and at low pressure ( 1 Torr) with a high ratio of SiH4 to WFg 

Reaction (1) is being replaced by a reaction where dichlorosilane is the silicon source. This provides better conformity and less cracking and peeling P lP l 

Another deposition reaction uses disilane as the silicon source at atmospheric pressure and at a deposition temperature of290-300°C, with nitrogen and hydrogen dilution as follows  

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Tungsten disilicide [12039-88-2] WSi2, forms bluish-gray tetragonal crystals (a = 0.3212 nm, c = 0.7880 nm). It is insoluble in water and melts at 2160°C. The compound is attacked by fluorine, chlorine, fused alkaUes, and HNO —HF. It may be used for high temperature thermocouples in combination with MOSi in an oxidising atmosphere. 

Tungsten Disilicide, WSig, is obtained by heating together copper silicide and amorphous tungsten in an electric furnace. The product is washed and treated successively with nitric acid, sodium hydroxide, warm hydrofluoric acid, and water. It may also be obtained by the aluminothermic process, by ignition of a mixture containing... 

Tungsten Disilicide (WSi2) tetragonal, D4jjl7 space group isomorphous with MoSi2 a=3.212 0.005A c=7.880 0.005... 

Silicides Molybdenum Disilicide (MoSi2) Tungsten Disilicide (WSi2) 6.24- 6.29 9.25- 9.3... 

Tungsten Disilicide (WSi2) Aluminum Oxide (AI2O3) Silicon Carbide (SiC) Vickers lOg 1632 kg/mm Vickers 20g 2600 kg/mm Vickers 25g 3000 3500 kg/mm ... 

Tungsten Disilicide (WSi2) Molybdenum Disilicide (MoSi2) Timgsten Monocarbide (WC) Vickers lOOg 1090 kg/mm Vickers lOOg 1290-1550 kg/mm Vickers lOOg 1730 kg/mm ... 

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