Abstract
The growth of gypsum is retarded by lanthanide ions present in the solution as impurities. The crystal faces show macrostep formation. At relative supersaturations of 0.2 the growth retarding influence of the ions decreases in the order La3+ ≈ Ce3+ ≈ Eu3+ > Er3+ > Cr3+ > Cr2O2-7, with a maximal difference of a factor 10 between the blank and La3+ at a concentration of 3 x 10-4M. At increasing supersaturations this difference becomes smaller and finally disappears at σ = 1. The uptake of lanthanides increases with increasing ionic radius, with a maximum for Ce3+. The sequences of growth retardation performance and uptake of the ions are therefore roughly similar. At higher supersaturations the uptake becomes higher. From the growth retardation as a function of the La3+ concentration an absorption energy of 30 kJ/mol was calculated. From adsorption experiments, no adsorption energy could be derived. The incorporation of Cd2+ ions in the presence of lanthanides behaves similarly as without these ions.
Original language | English (US) |
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Pages (from-to) | 70-78 |
Number of pages | 9 |
Journal | Journal of Crystal Growth |
Volume | 144 |
Issue number | 1-2 |
DOIs | |
State | Published - Nov 1994 |
Externally published | Yes |
ASJC Scopus subject areas
- Condensed Matter Physics
- Inorganic Chemistry
- Materials Chemistry