Nucleation and growth of AgCl clusters in a sodium borate glass: Numerical analysis and SAXS results

Abstract

By solving a set of differential rate equations the precipitation of AgCl clusters in the glass system 30Na2O–70B2O3/AgCl has been modeled. Using a parallel algorithm on a CRAY T3E it was possible to investigate the process of homogeneous nucleation and growth, which starts after an initial quench of the glass melt into the miscibility gap of the phase diagram, even including the onset of the Ostwald ripening stage. The method has been applied to the examination of the intermediate stage between independent growth and Ostwald ripening. In particular, the influence of the interfacial tension and the temperature of heat treatment on the evolution of the silver halide clusters has been investigated. The results are in qualitative agreement with those of in situ measurements of small-angle x-ray scattering. Furthermore, general consequences for the interpretation of experimental data on nucleation and growth have been derived.

Dynamics of first-order phase transitions in multicomponent systems: a new theoretical approach

“…The process of the evolution of the cluster size distribution in this particular system was analyzed for the first partly long ago [14,52] and extended to late stages of the evolution quite recently [53]. However, in these previous analysesfollowing the standard approach employed so far-it was assumed that the composition of the clusters is widely identical to the composition of the newly evolving phase.…”

“…In the determination of the parameters, we will refer here to segregation processes in glass-forming melts (segregation of an AgCl-phase in a sodium borate glass) investigated intensively earlier [52,53]. As a first parameter, we fix the average volume per particle as ω α = ω β ∼ = 4.89 × 10 −29 m 3 .…”

Неизотермическая нуклеация в твердом растворе CuCl в стекле: концентрационный эффект при нагреве твердого раствора

“…Образование новой фазы в твердом растворе при изо-термическом отжиге теоретически и экспериментально достаточно хорошо изучено [1][2][3][4][5][6]. Процессы выделения новой фазы в твердых растворах на стадии их разогрева до температуры изотермического отжига представляют собой важную и недостаточно изученную проблему.…”

On the theoretical description of nucleation in confined space

“…By this reason, a comparison of our approach with an earlier application 11 A similar to 11 but more comprehensive numerical analysis of the evolution of cluster size distributions in nucleation-growth processes was performed by us in 14,15 in order to interpret experimental results on segregation in solutions and in 16 in order to compare analytical computations on the characteristics of nucleation and growth processes 5,8 with results of numerical computations. These results of numerical computations are implemented also in Chapter 5 of the recent monograph 9 of one of the authors of the LSW-theory, V. V. Slezov.…”

“…2,11 The transition from nucleation to coarsening employing essentially the same equations is studied in detail in cited references. 9,[14][15][16] In their first fundamental theoretical analysis of Ostwald ripening, 12,17 Lifshitz and Slezov employed the term "coalescence" in a meaning identical to diffusion-limited or kinetic limited coarsening not accounting first initially for possible coagulation of large clusters. Such and a variety of additional effects have been incorporated later by Slezov and colleagues (c.f.…”