An X-ray diffraction study of the structure of di- and trichromate ions in solutions used for electrochemical chromium deposition
1992; Elsevier BV; Volume: 37; Issue: 7 Linguagem: Inglês
10.1016/0013-4686(92)85062-p
ISSN1873-3859
Autores Tópico(s)Iron oxide chemistry and applications
ResumoAn X-ray diffraction study was carried out in order to identify the predominant species in the CrO3-H2O system and industrial chromium electroplating bath. Structural parameters in terms of coordination numbers, average atom-atom distances and their mean square deviations were determined. Since the presence and distribution of polychromate molecules may have a significant effect on the bulk water structure, the di- and trichromate ratio can be evaluated only by having initially set certain solvent structure. Structural analysis performed by geometrical model construction and fitting it by means of a least-squares method to the experimental data, showed that dichromate ions have the maximum likelihood, but linear-shaped trichromate ions may also exist in significant concentration. It was confirmed that the industrial electrolyte does not contain unwanted, extremely stable [Cr(H2O)]3+ complex.
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