Europhys. Lett., 64 (5) , pp. 661-667 (2003)
Percolative conductivity in alkaline-earth silicate melts and glassesM. Malki1, M. Micoulaut2, F. Chaimbault1, Y. Vaills1 and P. Simon1
1 CRMHT-CNRS 1D - avenue de la Recherche Scientifique 45071 Orléans Cedex 02, France and Université d'Orléans - 45067 Orléans Cedex 02, France
2 Laboratoire de Physique Théorique des Liquides, Université Pierre et Marie Curie Boîte 121, 4 Place Jussieu, 75252 Paris Cedex 05, France
(Received 19 June 2003; accepted in final form 15 September 2003)
Ion-conducting ( ) x( ) 1-x glasses and melts show a threshold behaviour in dc conductivity near x=xt=0.50, with conductivities increasing linearly at x>xt. We show that the behaviour can be traced to a rigid ( x<0.50) to floppy ( x>0.50) elastic phase transition near x=xt. In the floppy phase, conductivity enhancement is traced to increased mobility or diffusion of carriers as the modified network elastically softens.
61.43.Fs - Glasses.
62.20.-x - Mechanical properties of solids.
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