Dynamic specific heat, glass transition, and non-Debye nature of thermal relaxation in lithium borate glasses

被引：15

作者：

Matsuda, Yu ^{[1
]}

Fukawa, Yasuteru ^{[1
]}

Ike, Yuji ^{[1
]}

Kodama, Masao ^{[2
]}

Kojima, Seiji ^{[1
]}

机构：

[1] Univ Tsukuba, Grad Sch Pure & Appl Sci, Tsukuba, Ibaraki 3058573, Japan

[2] Sojo Univ, Dept Appl Chem, Kumamoto 8600082, Japan

来源：

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN | 2008年 / 77卷 / 08期

基金：

日本学术振兴会;

关键词：

glass transition; non-Debye; stretched exponent; lithium borate glasses; dynamic specific heat; relaxation; temperature-modulated DSC;

D O I：

10.1143/JPSJ.77.084602

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The physical properties of lithium borate glasses, xLi(2)O center dot(100 - x)B2O3, vary anomalously with the lithium oxide content. known as "borate anomaly". In this study, the compositional variations of the dynamic glass transition temperature T-g(omega) and the non-Debye nature (or stretched exponentiality beta(KWW)) in the vicinity of T-g have been investigated over I wide composition range. Since T-g(omega) depends on the frequency of the temperature modulation, a more precise composition dependence can be discussed. The trend of T-g(omega) shows a sin-le broad maximum at about x = 26-28. Moreover, the composition dependence of the non-Debye behavior has been presented. It shows a broad maximum at about x = 40 mol %. It is found that beta(KWW) is systematically controlled using the fraction of each intermediate structural unit, particularly the tetrahedron composed of the 4-coordinated boron atom. Both the composition dependences of T-g(omega) and beta(KWW) can be explained using the structure-superposition model.

引用

页数：8