Europhys. Lett.
Volume 64, Number 5, December 2003
Page(s) 661 - 667
Section Condensed matter: structure, mechanical and thermal properties
Published online 01 November 2003
DOI: 10.1209/epl/i2003-00278-2
Europhys. Lett., 64 (5) , pp. 661-667 (2003)

Percolative conductivity in alkaline-earth silicate melts and glasses

M. 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 ( $\chem{CaO}$) x( $\chem{SiO_2}$) 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 $\chem{Ca^{2+}}$ carriers as the modified network elastically softens.

61.43.Fs - Glasses.
62.20.-x - Mechanical properties of solids.

© EDP Sciences 2003