INTECIN   20395
INSTITUTO DE TECNOLOGIAS Y CIENCIAS DE LA INGENIERIA "HILARIO FERNANDEZ LONG"
Unidad Ejecutora - UE
artículos
Título:
Crystallization process on amorphous GeTeSb samples near to eutectic point Ge15Te85
Autor/es:
J.ROCCA; M.ERAZU; M.FONTANA; B.ARCONDO
Revista:
JOURNAL OF NON-CRYSTALLINE SOLIDS
Editorial:
Elsevier
Referencias:
Año: 2009 vol. 355 p. 2068 - 2073
ISSN:
0022-3093
Resumen:
One of most important
properties of some tellurium-based chalcogenide glasses is the optical
and electrical switching between two states: the glass and the
crystalline state. The understanding in these systems of the glass to
crystal transition and its transformation kinetics is essential for
their application in non-volatile memories. GeTeSb and GeTe amorphous
samples of compositions close to the eutectic point Ge15Te85 were
obtained by rapid solidification from the liquid state employing
melt-spinning technique. The glass forming ability of this system, for
this cooling technique, is restricted to a small composition range
nearby the binary eutectic. The crystallization kinetics of the samples
was studied by means of differential scanning calorimetry (DSC) under
both isothermal and continuous heating regimes. The quenched samples
and the crystallization products have been characterized by X-ray
diffraction with Cu(Ka) radiation. The crystallization temperature,
activation energy, crystallization enthalpy and the dependence of these
properties on concentration are reported. The crystallization study of
Ge15Te85 glasses shows: a primary crystallization of Te superimposed
with a secondary crystallization of GeTe. The addition of Sb (5 at. %)
to the eutectic point Ge15Te85 modifies this behavior: the
crystallization of Ge13Sb5Te82 glasses consists on the crystallization
of Te and Ge2Sb2Te5 . The crystallization of the ternary glasses was
modeled.