Ergodicity breaking in strong and network-forming glassy systems
S. Caponi,a,b M. Zanatta,a A. Fontana,a,b L. E. Bove,c L. Orsingher,a,b F. Natali,d C. Petrillo,b,e e and F. Sacchettib,c
a Dipartimento di Fisica, Università di Trento, 38050 Povo, Trento, Italy
bResearch Center SOFT-INFM-CNR, c/o Università di Roma La Sapienza, 00185 Roma, Italy
cDepartement de Physique des Milieux Denses, CNRS-IMPC, Universit Paris 6, 75015 Paris, France
dINFM-OGG and CRS-SOFT c/o ILL, 6 rue Jules Horowitz, F-38042 Grenoble Cedex 9, France
eDipartimento di Fisica, Università di Perugia, 06100 Perugia, Italy
The temperature dependence of the non ergodicity factor of vitreous GeO2 , fQ (T ), as deduced from elastic and quasielastic neutron scattering experiments, is analyzed. The data are collected in a wide range of temperatures from the glassy phase, up to the glass transition temperature, and well into the undercooled liquid state. Notwithstanding the investigated system is classified as prototype of strong glass, it is found that the temperature and the Q behavior of fQ (T ), follow some of the predictions of mode coupling theory. The experimental data support the hypothesis of the existence of an ergodic to nonergodic transition also in network-forming glassy systems.