Isothermal phase transformation kinetics in stoichiometric GeSbTe thin films

摘要

The purpose of this work is to investigate the isothermal phase transformation in thin films of Ge2Sb2Te5 and Ge1Sb2Te4 alloys. From experimental and computed simulations it was shown that if the kinetic behavior is interpreted employing the Johnson-Avrami-Mehl-Kolmogorov theory, three slopes can be observed: the first related to a metastable transformation, the second to the step between metastable and stable transformation, and the last to the stable phase nucleation and growth. From X-ray patterns it was found that a metastable phase, which appears during the beginning of crystallization for Ge2Sb2Te5 and Ge1Sb2Te4 thin films, corresponds to the Ge1Sb4Te7 fcc composition. (C) 2004 Elsevier B.V. All rights reserved.