Variety of Aggregation and Growth Processes of Lanthanum Fluoride as a Function of La/F Activity Ratio. 1. Potentiometric pF-Stat and DLS Study of LaF3
| Autor: | Nada Stubičar |
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| Rok vydání: | 2004 |
| Předmět: | |
| Zdroj: | Crystal Growth & Design. 5:113-122 |
| ISSN: | 1528-7505 1528-7483 |
| Popis: | The constant composition method, in particular the potentiometric pF-stat method, was proved to be applicable and convenient to study the kinetics of submicrometer size lanthanum fluoride particles besides that of macroscopic crystals. The state of ions in supersaturated solution (due to hydrolysis and other chemical reasons) (La-to-F ratio, the attained pH, ionic strength, temperature, the way and speed of mixing, etc.) was kept constant during the whole growth process. Steady-state kinetics was achieved after about 150% of growth as regards the initial mass of seeds. Because of very reproducible results, this method is prominent for the preparation of new materials with respect to morphology and microstructure, even in nanosize scale (parts 1 and 2), far from thermodynamic equilibrium and at nonstoichiometric condition. Depending on the activity ratio of La- to F-ions in supersaturated solution used for particle growth, i.e., whether lanthanum nitrate or potassium fluoride is in a great excess, the kine... |
| Databáze: | OpenAIRE |
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