The phase transformation and crystallization kinetics of (1-x)Li2O-xNa2O-Al2O3-4SiO2 glasses

The phase transformation and crystallization kinetics of (1 x)Li2O-xNa(2)O-Al2O3-4SiO(2) glasses have been studied by using differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron diffraction (ED) analysis. The crystallization temperature at the exothermic peak increases from 1171 to 1212 K when the Na2O content increases from 0 to 0.6 mol. The crystalline phase is composed of spodumene crystallization when the Na2O content increases from 0 to 0.6 mol. The activation energy of spodumene crystallization decreases from 444.0 +/- 22.2 to 284.0 +/- 10.8 kJ mol(-1) when the Na2O content increases from 0 to 0.4 mol. Moreover, the activation energy increases from 284.0 +/- 10.8 to 446.0 +/- 23.2 kJ mol(-1) when the Na2O content increases from 0.4 to 0.6 mol. The crystallization parameters m and n approach 2, indicating that the surface nucleation and two-dimensional growth are dominant in (1-x)Li2O-xNa(2)O-Al2O3-4SiO(2) glasses. (C) 2010 Elsevier B.V. All rights reserved.