https://doi.org/10.1140/epjb/e2014-50176-3
Regular Article
Pressure-induced structural transition in amorphous GeO2: a molecular dynamics simulation
1 Departamento de Física, Facultad de
Ciencias Exactas, Universidad Andrés Bello, Santiago,
Chile
2 Departamento de Física, Facultad de
Ciencias, Universidad de Chile, Casilla 653, Santiago, Chile
a e-mail: joaquin.peralta@unab.cl
Received:
15
March
2014
Received in final form:
23
August
2014
Published online:
3
November
2014
We studied the structural and dynamical properties of amorphous germanium dioxide (GeO2) from low to high pressure by means of the classical molecular dynamics technique. The simulations were done in the micro-canonical ensemble, with systems at densities ranged from 3.16 to 6.79 g/cm3, using a pairwise potential. The network topology of the systems is analyzed at atomic level through partial pair correlations, coordination number and angular distributions. The dynamic properties were characterized by means of the vibrational density of states. According the density increases, a structural transformation from a short-range order, defined by a building block composed by a basic (GeO4) tetrahedron, to a basic (GeO6) octahedron is observed. The vibrational density of states also presents important changes when the density increases, with a low frequency band lessened, and a high density band wider and flatter.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2014