University of North Texas 
W. Brostow, V.M. Castano, G. M. Barrera, J.M. Saiter
a) Laboratory of Advanced Polymers and Optimized Materials (LAPOM), Department of
Material Science and Engineering, University of North Texas, Denton, TX 76203-5310,
USA
b) Centro de Fisica Aplicada y Tecnologia Avanzada (CFATA), Universidad Nacional Autonoma
de Mexico, A.P. 1-1010, Queretaro, Qro. 76001, Mexico
c) Posgrado de la Facultad de Quimica, Universidad Autonoma del Estado de Meixco,
A.P. A- 20, Toluca, Estado de Mexico 50000, Mexico
d) Laboratoire d'etude et de Caracterisation des Amorphes et des Polymeres (LECAP),
Universite de Rouen, site du Madrillet, Avenue de l' Universite, BP12, 76801 Saint
Etienne du Rouwray, France
ABSTRACT
We have studied the vitreous GexSe1-x chalcogenide alloys, varying from x from 0.0 to 0.12. P-V-T results have been obtained for pressures up to 200 J cm-3 and temperatures up to 240C or so. The P*, V*, and T* parameters of the Hartman equation of state (EOS) were evaluated. With increasing Ge concentration the specific volume increases, passes through a maximum and then decreases. By contrast, the characteristic (hard- core) volume V* passes through a minimum and so does the characteristic temperature T*. On the basis of these results in conjunction with earlier ones we provide an expanded model of atomic packing and phase structures of the alloys.
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