Pantheon SEMPARIS Le serveur des séminaires parisiens Paris

Statut Confirmé
Domaines cond-mat
Date Vendredi 24 Juin 2011
Heure 10:30
Institut IMPMC
Salle 4ème étage, Tour 22-23, Salle 1, IMPMC, ,Univ. P. et M. Curie, 4, Place Jussieu
Nom de l'orateur Boolchand
Prenom de l'orateur P.
Addresse email de l'orateur
Institution de l'orateur University of Cincinnati
Titre Elastic phase transitions in alkali modified oxide glasses
Résumé Chemical bonds in networks act as atomic constraints (both bond-bending and bond stretching kind) in assembling disordered solids. The count of constraints/atom has proved to be the single most significant parameter to understanding the physics of glasses including the elusive glass transition. These ideas have led to the recognition of two distinct elastic phase transitions- a rigidity and a stress transition as the count of constraints/atom is steadily increased either by chemical alloying or applying hydrostatic pressure. Experiments designed as test of these basic ideas show existence three elastic phases- flexible, intermediate and stressed rigid in semiconducting glasses with characteristic thermal, optical and mechanical signature. In alkali-modified-silicates,-germanates and -borates, these ideas show that packing considerations determined by alkali-ion size apparently control elastic phase diagrams in connectivity space. We provide examples.
Numéro de preprint arXiv
Fichiers attachés

Pour obtenir l' affiche de ce séminaire : [ Postscript | PDF ]

[ Annonces ]    [ Abonnements ]    [ Archive ]    [ Aide ]    [ ]
[ English version ]