Effects of pressure on the fragile nature of fluorozirconates studied by molecular dynamics simulations.
Molecular dynamics simulations for a multicomponent zirconium fluoride, ZBEN (55ZrF(4)-17BaF(2)-5EuF(3)-23NaF) have been carried out at various temperatures and pressures including those of the molten and glassy states. The effect of pressure on the fragile nature of ZBEN was investigated. The relaxation times were calculated from the decay curves of the intermediate scattering function. The fragile nature of ZBEN was reflected by the obvious non-Arrhenius behavior in the temperature dependence of the relaxation time. The so-called "Angell plot" of the relaxation time was represented by a single curve irrespective of applied pressure; the fragile nature changes negligibly with pressure. This seems to contradict the enhancement of the connectivity of ZrF(n) polyhedra under high pressure. The origin of the pressure effects is discussed in comparison with those for molecular liquids and covalent-network glasses.
Tamai
Yoshinori
Y
Department of Applied Physics, Faculty of Engineering, Fukui University, Fukui 910-8507, Japan. tamai@polymer.apphy.fukui-u.ac.jp