The structural inhomogeneity of lead-cadmium fluoride systems and its implications.

In this paper we present a detailed study of structural and dynamical properties of the CdF(2)-PbF(2) systems. Particular attention is devoted to the processes involving the phase separation, a phenomenon of fundamental importance in the correct description of some dynamical properties, as introduced in our previous works. We show here, that the phase separation trend is observed in the undercooled melt, whether by cooling the liquid below its melting point, or by heating a homogeneous glass at temperatures above T(g).

Structural ordering in Cd(x)Pb(1-x)F2 alloys: a combined molecular dynamics and solid state NMR study.

Molecular dynamics (MD) simulations of binary Cd(x)Pb(1-x)F(2) alloys have been carried out, using a two-body Buckingham interaction potential, leading to a correct description of structural properties as a function of composition and pointing towards an understanding of the eutectic phenomenon. The simulation data can be analyzed in terms of five local fluorine environments Q((n)) (4> or =n> or =0), where n is the number of Pb nearest-neighbor environments. The results suggest a highly nonstatistical population distribution, suggesting an intrinsic phase segregation tendency in the undercooled melt, during the cooling process.