Crystal nucleation and growth kinetics in a fresnoite glass: First measurements

Internal nucleation and growth kinetics of fresnoite crystal (2BaO.TiO2.2SiO(2)) in an almost stoichiometric fresnoite glass were determined for the first time. Nucleation densities and crystal size distributions were estimated by Scanning Electron Microscopy (SEM), instead of the conventional technique, due to the extremely high nucleation rates (10(17)m(-3)s(-1)) and small crystal sizes (2-500nm). A modified stereological equation coupled to SEM micrographs were used to estimate crystal nucleation and growth. The consistency of the experimental nucleation and growth rates were determined by comparing the time evolution of the experimental crystallised volume fractions with the values calculated by the JMAK theory. Fresnoite glass displays the highest nucleation rates sc far measured in inorganic glasses and can lead to nano glass-ceramics.