The influence of the distribution of water in silicate glasses on mechanical relaxation

Taylor, Theodore D.; Rindone, Guy E.

doi:10.1016/0022-3093(74)90026-x

Cited by 20 publications

(5 citation statements)

References 6 publications

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“…As those four obtained DE could be considered as values close to each other (average 207 kJ/mol), the relaxation mechanism was considered to be almost the same mechanism. Various mechanisms have been reported [18][19][20][21] for explanation of the high temperature peaks; however, the final explanation is still missing. As the DE are rather high values compared with DE obtained from the primary peaks, it is presumed that the relaxation mechanism is different from that of the primary peak groups.…”

Section: Resultsmentioning

confidence: 99%

Internal friction and dynamic modulus of metaphosphate glass

Sakamura

Kobayashi

Ozawa

et al. 2004

Journal of Non-Crystalline Solids

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Section: Resultsmentioning

confidence: 99%

Internal friction and dynamic modulus of metaphosphate glass

Sakamura

Kobayashi

Ozawa

et al. 2004

Journal of Non-Crystalline Solids

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“…Makled and Kreidl [92], and Doremus [93] linked this maximum to the presence of water in glasses, and Day and others [94,95,96,97] proposed that this maximum is caused by 'cooperative' motion of alkali ions and protons, similar to that suggested to explain the origin of so-called 'mixed alkali peak' in mechanical losses of mixed alkali glasses, this ascription seems to be incorrect since such a maximum is observed also in mechanical loss spectra of glasses whose IR spectra show them to be essentially anhydrous [73]. In addition, dielectric relaxation measurements which are usually used to qualify the response of the material to a field-induced perturbation revealed only maxima attributable to the motion of alkali ions and showed no response corresponding to the orientational polarization of dipoles proposed to be the centers responsible for this maximum [98,99,100,101].…”

Section: Mmie In Viscosity T G and Mechanical Loss Spectramentioning

confidence: 99%

Defect model for the mixed mobile ion effect

Belostotsky¹

2007

Journal of Non-Crystalline Solids

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This paper presents a new defect model for the mixed mobile ion effect. The essential physical concept involved is that simultaneous migration of two unlike mobile ions in mixed ionic glass is accompanied by expansion or contraction of the guest-occupied sites with distortion of surrounding glass matrix; in many cases, an intensity of the local stresses in glass matrix surrounding ionic sites occupied by foreign ions is much greater than, or at least comparable to the glass network binding energy. Hence, when the stress exceeds the breaking threshold, relaxation occurs almost immediately via the rupture of the bonds in the nearest glass matrix with generation of pairs of intrinsic structural defects. The specificity of the mechanism of defect generation leads to the clustering of negatively charged defects, so that rearranged sites act as high energy anion traps in glass matrix. This results in the immobilization of almost all minority mobile species and part of majority mobile species, so mixed mobile ion glass behaves as single mobile ion glass of much lower concentration of charge carriers. Generation of defects leads also to the depolymerization of glass network, which in turn results in the reduction of the glass viscosity and Tg as well as in the compaction of glass structure (thermometer effect). The magnitude of the mixed mobile ion effect is defined by the size mismatch of unlike mobile ions, their total and relative concentrations, the binding energy of the glass-forming network, and temperature. Although the proposed model is based upon the exploration of alkali silicate glass-forming system, the approach developed here can be easily adopted to other mixed ionic systems such as crystalline and even liquid ionic conductors.Comment: 33 pages, 2 figure

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“…The above-mentioned fact strongly suggests that H + in phosphate glasses is much more mobile than alkali ions [11]. Several mechanisms were reported in previous literature, explaining the low temperature internal friction peaks in another metaphosphate glass [12][13][14]. However, the detailed relaxation mechanism is not clear yet.…”

Section: Discussionmentioning

confidence: 82%