CESIUM HALIDES

Vapor pressure of cesium halides was reported by Yaws [4], see Table

The application of CsCl and CsBr as doped catalysts for CVD of carbon nanotubes was reported by Nemeth at al. Doping with Cs halides allowed to deposit carbon more efficiently at higher yield.  The amount of dopant alkali compounds was in the range 1-5%. [80]

Cesium chloride CsCl

Fig. Vapor pressure of CsCl

Cesium chloride CsCl (M = ) is solid having vapor pressure :

 Log10P(Torr) = A - B/T + C log10T + D T + E T2 (T, K)

A =438,8475; B =-3.4903E4, C =-150.08; D =0.053499; E =-7.34E-6, Tmin = K (744°C), Tmax =  K (1300°C)

Cesium bromide CsBr

Fig. Vapor pressure of CsBr

Cesium bromide CsBr (M = ) is solid having vapor pressure :

Log10P(Torr) = A - B/T + C log10T + D T + E T2 (T, K),

A =1537,65; B =-1,06E+5, C =-5,29E2; D =1,80E-1 ; E =-2,34E-5, Tmin = K (748°C), Tmax =  K (1300°C)

CsCl, CsBr for Cs –doped carbon nanotube CVD

      Cesium chloride CsCl and cesium bromide CsBr (and for comparison KCl, KBr) were applied as cesium sources for  the growth of Cs –doped carbon nanotubes by CVD.  Doping alkali compounds (CsBr, CsCl) allowed to reach higher carbon deposit and carbon yield; the amount of the dopants varied from 1 to 5%. As prepared CNTs were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman microscopy.[i]

[i] K. Nemeth, Z. Nemeth, D. Fejes, B. Reti, Z. Balogh, K. Hernadi, Phys. Status Solidi (b), 2011, Vol.248, Iss. 11, p. 2471–2474 , « The effect of alkaline doped catalysts on the CVD synthesis of carbon nanotubes », http://onlinelibrary.wiley.com/doi/10.1002/pssb.201100077

Cesium iodide CsI

Cesium iodide CsI (M = ) is solid having vapor pressure :

Log10P(Torr) = A - B/T + C log10T + D T + E T2 (T, K)

A =276,4031; B =--2,62E4, C =-9,24E1; D 3,8E-2; E =--4,04E-6, Tmin = K (738°C), Tmax =  K (1280°C)

Cesium fluoride CsF

Fig. Vapor pressure of CsF

Cesium fluoride CsF (M = ) is solid having vapor pressure :

Log10P(Torr) = A - B/T + C log10T + D T + E T2 (T, K)

A =1768,1436; B =-1,18E5, C =-6,11E2; D = 2,13E-1; E =--2,83E-5, Tmin = K (712°C), Tmax =  K (1280°C)

CsI, CsF for Cs –terminated diamond CVD

      Cesium iodide CsI and cesium fluoride CsF were applied for the preparation of cesium terminated chemical vapor deposited (CVD) diamond films, however Cs deposition process itself was performed not by CVD but by e-beam evaporation of CsI, CsF –coated targets. The electron beam induced iodine depletion (chemical reaction on the diamond surface) after short beam exposures, leaving a Cs terminated diamond surface independent of the initial CsI or CsF target thickness.(as was studied by Auger electron spectroscopy).  Stable secondary electron emission from Cs-terminated diamond films was observed; 25 to 50 total secondary yield coefficients (σ) were achived, they  were stable (tested up to 170 h) under continuous exposure of targets to an electron beam. Primary current densities ranged from 1.5 to 50.0 mA/cm2.[i]

[i] G. T. Mearini, I. L. Krainsky;  J. A. Dayton;  Yaxin Wang;  Ch.A. Zorman;  J.C. Angus;  R.W. Hoffman;  D. F. Anderson, Appl. Phys. Letters, 1995, Vol. 66, Iss.2, p. 242 – 244, « Stable secondary electron emission from chemical vapor deposited diamond films coated with alkali‐halides » 

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