Publication Details:

Established in 2008

Journal or Publication Title:

Armenian Journal of Physics=Ֆիզիկայի հայկական հանդես

Date of publication:

2010

Volume:

3

Number:

3

ISSN:

1829-1171

Official URL:

Coverage:

218-235

Abstract:

Differential thermal analysis (DTA) under non-isothermal conditions, density and Vicker's hardness techniques have been employed to investigate the effect of different MnO2 contents on the thermal transitions data, hardness, Hv, glass-forming ability, GFA, stability, GS, fragility, Fi and activation energy of glass transition, Eg of 40SiO25Al2O355Na2O glass. The dependence of the characteristic temperatures “glass transition temperature” (Tg), the crystallization onset temperature (Tx) and the crystallization temperature (Tc)” on the heating rate (β) were utilized in the determination of the activation energy for the glass transition (Eg), the glass thermal stability (KH and m) and the fragility, Fi. Three approaches were used to analyze the dependence of glass transition temperature on the heating rate (β) and another two were used to calculate the fragility parameter (Fi). The composition dependence of the Tg, density, Eg, Hv, GFA and Fi were discussed in the light of different oxidation states of manganese ions and its influence on the structure of the glasses. The indicative parameters of GFA, ΔTx, Trg, KH, m and Hv were increased with the addition of MnO2 up to 0.4 mol%, and decreased beyond 0.4 mol% MnO2. The glass activation energies had lower values in MnO2 content up to 0.4 mol% which are in good agreement with the fragility parameter Fi values. Then the addition of low amount of MnO2 up to 0.4 at% MnO2 in 40SiO25Al2O355Na2O glass at the expense of Na2O may improve the glass-forming ability, thermal stability, the rigidity of the glass network and the glass sample S3 is the best GFA and stability with higher Hv and kinetically strong-glass forming (KS).

Date created:

2010

Format:

pdf

Identifier:

oai:arar.sci.am:23278

Location of original object:

ՀՀ ԳԱԱ Հիմնարար գիտական գրադարան