Effect of impurities on the metastable zone width of solute–solvent systems
Artykuł w czasopiśmie
| Status: | |
| Autorzy: | Sangwal Keshra |
| Rok wydania: | 2009 |
| Wersja dokumentu: | Drukowana | Elektroniczna |
| Język: | angielski |
| Numer czasopisma: | 16 |
| Wolumen/Tom: | 311 |
| Strony: | 4050 - 4061 |
| Web of Science® Times Cited: | 50 |
| Scopus® Cytowania: | 53 |
| Bazy: | Web of Science | Scopus |
| Efekt badań statutowych | NIE |
| Materiał konferencyjny: | NIE |
| Publikacja OA: | NIE |
| Abstrakty: | angielski |
| The novel approach to interpret the metastable zone width obtained by the polythermal method using the classical theory of three-dimensional nucleation proposed recently [K. Sangwal, Cryst. Growth Des. 9 (2009) 942] is extended to describe the metastable zone width of solute–solvent systems in the presence of impurities. It is considered that impurity particles present in the solution can change the nucleation rate J by affecting both the kinetic factor A and the term B related with the solute–solvent interfacial energy γ. An expression relating metastable zone width, as defined by the maximum supercooling ΔTmax of a solution saturated at temperature T0, with cooling rate R is proposed in the form: (T0/ΔTmax)2=F(1−Z ln R), where F and Z are constants. The above relation can also be applied to describe the experimental data on maximum supercooling ΔTmax obtained at a given constant R as a function of impurity concentration ci by the polythermal method and on maximum supersaturation σmax as a function of impurity concentration ci by the isothermal method. Experimental data on ΔTmax obtained as a function of cooling rate R for solutions containing various concentrations ci of different impurities and as a function of concentration ci of impurities at constant R by the polythermal method and on σmax as a function of impurity concentration ci by the isothermal method are analyzed satisfactorily using the above approach. The experimental data are also analyzed using the expression of the self-consistent Nývlt-like approach [K. Sangwal, Cryst. Res. Technol. 44 (2009) 231]: ln(ΔTmax/T0)=Φ+β ln R, where Φ and β are constants. It was found that the trends of the dependences of Φ and β on impurity concentration ci are similar to those observed in the trends of the dependences of constants F and Z on ci predicted by the approach based on the classical nucleation theory. |
