Influence of particle size of glass powder on the crystallisation kinetic parameters of a fluorophosphate glass

Crystallisation behaviour of a fluorophosphate glass composed of the system AIF(3)-CaF2-Mg-2-Sr-2- BaF2-Ba(PO3)(2) was studied at nonisothermal condit ions using differential thermal analysis (DTA). Kinetic parameters for crys tallisation, namely, the activation energy, E, frequency factor; upsilon, a nd Avrami exponent, n, were determined as a function of the particle size o f the glass powder and different furnace atmosphere. Also the Effect of flo w rate of nitrogen gas on the crystallisation behaviour was studied Results are analysed in ter nu of a theory applicable to nonisothermal crystallisa tion kinetics. E, upsilon and n decreased as particle size of the glass pow der increased. Furnace atmosphere and flow rate of nitrogen gas did not hav e a significant effect on the kinetic parameters.