ISSN:
0268-2605
Schlagwort(e):
Rochow reaction
;
copper silicides
;
η-Cu3Si
;
promoters
;
scanning electron microscopy (SEM)
;
energy-dispersive X-ray spectroscopy (EDX)
;
scanning Auger microscopy (SAM)
;
Auger electron spectroscopy (AES)
;
Chemistry
;
Industrial Chemistry and Chemical Engineering
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Appropriate Rochow contact masses have been investigated by the spatial resolution techniques SEM-EDX and SAM-AES. The results gave evidence of the existence and the catalytic action of (X-ray)-amorphous copper-silicon (Cu-Si) surface species, i.e. extremely highly dispersed particles or two-dimensional species. The well-known Rochow promoter zinc seems to act as a moderator rather than as a real accelerator. It ensures a stable rate for the reaction by neutralizing the detrimental action of silicon impurities. The silicon impurities make the whole of the silicon surface reactive and in this way cause a general blockade of the silicon surface by inactive copper species. Zinc localizes the reaction. The silicon surface remains partly free, and active Cu-Si surface species can be formed by lateral diffusion of copper onto the silicon surface that is still free. © 1997 by John Wiley & Sons, Ltd.
Zusätzliches Material:
7 Ill.
Materialart:
Digitale Medien
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