11B MAS NMR spectroscopic study of structural relaxation, aging, and memory effect at the atomic scale in a borosilicate glass
Journal of Physical Chemistry B, cilt.111, sa.33, ss.9758-9761, 2007 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 111 Sayı: 33
- Basım Tarihi: 2007
- Doi Numarası: 10.1021/jp072223i
- Dergi Adı: Journal of Physical Chemistry B
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.9758-9761
- Boğaziçi Üniversitesi Adresli: Hayır
Özet
Relaxation kinetics of boron coordination environments in a borosilicate glass in response to temperature jumps has been monitored using 11B magic-angle spinning (MAS) NMR spectroscopy. The relaxation time scale of the BO4/BO3 ratio is found to be closely comparable with those of the bulk properties, namely, refractive index and viscosity, showing a close connection with one another. Samples partially equilibrated at a low temperature, when subjected to a positive temperature jump, display an initial rapid decrease followed by an increase in the BO4/BO3 ratio. This reversal in the trend of the variation of the BO4/BO 3 ratio has been interpreted to be the signature of a memory effect, and the implications are discussed within the framework of the potential energy landscape model of glassy dynamics. © 2007 American Chemical Society.