Variation of Avrami parameter during non-isothermal surface crystallization of glass powders with different sizes

Comments on “Kinetics of non-isothermal crystallization and glass transition phenomena in Ga10Se87Pb3 and Ga10Se84Pb6 chalcogenide glasses by DSC” by Al-Agel et al.

“…The grain size is considered as extremely important factor to the value to attribute to the parameter n in the KJMA kinetic Eq. (6), as reported by Karamanov et al [12]. Also, we found no justification for declaration of m = 2, for the investigated Ga-Se-Pb glasses.…”

Textured and hierarchically structured calcium phosphate ceramic blocks through hydrothermal treatment

“…5e and Table 1). Indeed, good fits of the experimental curves were obtained with Avrami's equation using a value of 1 for the n parameter, which indicate punctual nucleation and linear progression of phase conversion [72]. Using Avrami's equation, it was possible to calculate the activation energies for each phase conversion.…”

Influence of Particle Size on Nonisothermal Crystallization in a Lithium Disilicate Glass

“…Taking into account the findings of Marota et al ., Ray et al . assumed that the activation energy does not change with particle size. Matusita & Sakka and Karamanov et al . found that the values of crystallization activation energy obtained for LS 2 and 54SiO 2 ·2Al 2 O 3 ·21CaO·21MgO·2Na 2 O (%mol) glasses, respectively, decreased as the particle size increased because of the change in the corresponding crystallization mechanism.…”

“…Recently, Karamanov et al 10 investigated the influence of particle size on the crystallization mechanisms in a glass with a composition of 54SiO 2 Á2Al 2 O 3 Á21CaOÁ21MgOÁ2Na 2 O (% mol), which is characterized by a surface crystallization of 60 wt% diopside (CaOÁMgOÁ2SiO 2 ) and by the formation of 8-10 vol% porosity during crystallization. Nonisothermal DTA analysis showed that the activation energy for crystallization decreased as the particle size increased.…”