Secondary relaxation behavior in a strong glass.
In the present paper we study the enthalpy relaxation behavior of the hyperquenched GeO(2) (HQGeO(2)) glass, one of the strongest glass systems. By applying the hyperquenching-annealing-calorimetry approach, we have found that unlike fragile glasses the strong HQGeO(2) glass relaxes in a manner that all the secondary relaxation units contribute to the primary relaxation. By analyzing dynamic properties of the secondary relaxation, we have identified two typical features of the Johari-Goldstein relaxation in the HQGeO(2) glass. First, the quantitative relationship observed here between E(beta) and T(g) agrees well with the empirical relation of the JG relaxation. Second, the characteristic relaxation time of the GeO(2) glass at T(g) is found to be about 10 s, larger than that of relatively fragile glasses. These results verify that the JG peak in strong glasses is hidden by the alpha peak in the dielectric loss curves.
Hu
Lina
L
Key laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061, China.
Yue
Yuanzheng
Y