Evaluation of the concentration of boroxol rings in vitreous B2O3 by the stochastic matrix method

A statistical model in which the stochastic matrix method is applied is used to find the fraction of boron atoms belonging to boroxol rings in a boron oxide (B2O3) glass. The method also enables one to evaluate the characteristic energies related to the formation of a single B-O-B unit in an oxygen bridge or in a boroxol ring. The qualitative behaviour of the heat capacity C-p(T) during the glass transition is reproduced, with the inflexion point at the temperature given by the experiment. The model also gives a reasonable qualitative prediction for a characteristic exponent ruling the growth of microclusters, which may in turn be related to the specific volume.