The kinetics of crystal nucleation in anorthite (CaAl2Si2O8) have been determined over the range of undercooling between 475 and 600°C. The plot of In(Ivη) versus (ΔT|staggered|r2T|staggered|r3)-1 is a straight line of negative slope over the temperature range investigated. The slope of this relation indicates a free energy barrier to crystal nucleation of about 82 kT* (where T* = 0.8TE). The intercept at (ΔT|staggered|r2Tstaggered|r3)-1 = 0 is approximately 1027 cm-3 s-1P. Samples of anorthite glass were also analyzed by differential thermal analysis, with the temperature of maximum crystallization rate being determined as a function of heating rate. From this variation, a nucleation barrier of about 80 kT* was estimated. The combined results are in good agreement with predictions of the classical theory of homogeneous nucleation.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry