chemical physics of discharges - Argonne National Laboratory

epcrte? the noss~kil.itv of nroduct-r carton bla ck fror hvdrocarbons usinp a nlnsna
'et. !!ethane or other hvtrccarbons which would h e introduced intc the plasma flane,
uoul? be cracke2 usir.;. tvCro.ren as the ooeratinr vas an? Droducirp carbon black.
LicciC as i.re11 3s' Fzseous h-:?rncar!mns car te cse? 5s a source for carbon and the
'.'itrc khoratories (4) have exnerinente? ;iith carton Slack production frnv linuic!
h:idrocarhons.
'P"?O5 + !Z1 j Ta (8)
\!C3 t 4 :.: ' (9)
~ 1 3 + 0 Y~/CE,,+ ~
PI (10)
re0 + U7+ ?e (11)
The nroduction of metal nitrides (F! f* 17) from the elements has been
invest ipated for three elements, titanium, -arrnesiun and tunpsten (reactions 1 to 3).
The Droduction of titaniun nitride in the 1000. vield was accovplished bv usinp 200
mesh titaniur Dowder fed into a nitrooen Dlasna ;et. The titanium nitride particle
size was found to be 0.75 to 7.5 microns and the nroduct was also formed in larpe,
corpact, Folden .rellov crvstals. In a like manner tunpsten nitride was formed in
75p yield. 40% conversion to rnapnesiun nitride was obtained when nacnesium was
fed into a nitropen olasma jet.
The preDaration of'cetal carbiles has also been reDorted (12 6 17). Tipure
5 shovs the 9 conversion VS. Kwhr/a tunasten input for reaction 4. As can be seen,
the XC conversion is directlv Dronortional to the power input level. The hiRhest
conversions obtained were 43? for \,!2r and 11% for %'C. reaction 5 aSove is shown in
riplire 6 uhere .9. conversion is plotter] VS. Kwhr/v !XI3 innut. The three products of
the reaction, tunrsten (43 to Rl? cnnversicn), tunester. carhide (4 to 11% oonversion)
and ditunesten carbide (9 to 35% conversion) are fomad in a total conversion of 81
to 9UQ.. ?e naior Droduct is tiinosten which is'favored at higher Kwhr/p WOg inputs.
The reaction of tantalum and methane in a helium nlasma jet is shown in Fipure 7 where
a water-cooled cuenchinp nroba was ~ l ~ c at e d 1/3" and 5" below the plasma jet. The
effect of the ruenchinr distance is dranatic. The annunt of Ta2C formed is notapDrecfahlv
different in either case, however, the TaC vield chanped considerably bv
the n1acerrer.t of the ouenchinp device. Conversions UD to 72% have been produced
by this reaction. Tipure e shows a nlot of the tantalur-pentoxide plus nethane
reaction carried o ut in a helitic Dlasma jet. The % conversion is plotted vs. Kwhr/y
tantalun nentoxide input for two different ouenchinp nrobe distances frm the plasma
iet. Jn the case where the auencher was 1/7" 5elow the jet the Droduction of TaC