Observation of polyamorphism in the phase change alloy Ge1Sb2Te4

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Kalkan B., Sen S., Cho J. -., Joo Y. -., Clark S. M.

APPLIED PHYSICS LETTERS, vol.101, no.15, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 101 Issue: 15
  • Publication Date: 2012
  • Doi Number: 10.1063/1.4759106
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Hacettepe University Affiliated: No


A high-pressure synchrotron x-ray diffraction study of the phase change alloy Ge1Sb2Te4 demonstrates the existence of a polyamorphic phase transition between the "as deposited" low density amorphous (LDA) phase and a high density amorphous (HDA) phase at similar to 10 GPa. The entropy of the HDA phase is expected to be higher than that of the LDA phase resulting in a negative Clapeyron slope for this transition. These phase relations may enable the polyamorphic transition to play a role in the memory and data storage applications. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4759106]