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Heating rate effects in time-dependent homogeneous nucleation in glasses
- Source :
- Journal of Non-Crystalline Solids. 474:1-8
- Publication Year :
- 2017
- Publisher :
- Elsevier BV, 2017.
-
Abstract
- Nucleation kinetics of glass-ceramics is frequently determined using Tammann's double-stage heat-treatment. This method requires a complex deconvolution of the experimentally observed induction time (tind), i.e. the intercept of the linear part of the crystal number density curve with the nucleation time axis, into two components. In this paper, double-stage heat treatments were performed, with heating rates between the nucleation and development temperatures covering two orders of magnitude, in samples of a homogeneously nucleating glass-forming system, lithium disilicate. Our results show that tind increases with increasing heating rates with cubic root dependence. In accordance with the theory, tind was split into the intrinsic time required to establish a steady-state cluster size distribution, τ (time-lag) at the nucleation temperature and an incubation time (ti), which is a size, heating rate and development temperature (Td) dependent growth time. We demonstrate that the Collins-Kashchiev nucleation model performs poorly if ti is approximated by the time needed to experimentally detect the first crystal. In contrast, the Shneidman approach is consistent with theory. We found that at any given nucleation temperature, ti is a strong function of the heating rate, and is proportional to tind, whereas τ is a constant, as expected.
- Subjects :
- 010302 applied physics
Materials science
Number density
Nucleation
Thermodynamics
02 engineering and technology
Function (mathematics)
021001 nanoscience & nanotechnology
Condensed Matter Physics
01 natural sciences
Electronic, Optical and Magnetic Materials
Crystal
Crystallography
Homogeneous
0103 physical sciences
Materials Chemistry
Ceramics and Composites
Cluster size
0210 nano-technology
Constant (mathematics)
Order of magnitude
Subjects
Details
- ISSN :
- 00223093
- Volume :
- 474
- Database :
- OpenAIRE
- Journal :
- Journal of Non-Crystalline Solids
- Accession number :
- edsair.doi...........d5f797247cd0ce9656ced81d50869cfe