Notes on Reproducibility of Ge 2 Sb 2 Te 5 Properties

Atomistic origins of the phase transition mechanism in Ge(2)Sb(2)Te(5)

Density functional study of amorphous, liquid and crystalline Ge(2)Sb(2)Te(5): homopolar bonds and/or AB alternation?

The amorphous, liquid and crystalline phases of the phase change material Ge(2)Sb(2)Te(5) (GST) have been studied by means of density functional/molecular dynamics simulations. The large sample (460 atoms and 52 vacancies in the unit cell) and long simulations (hundreds of picoseconds) provide much new information. Here we extend our original analysis (2007 Phys. Rev. B 76 235201) in important ...

Toward the Ultimate Limit of Phase Change in Ge₂Sb₂Te₅

The limit to which the phase change memory material Ge2Sb2Te5 can be scaled toward the smallest possible memory cell is investigated using structural and optical methodologies. The encapsulation material surrounding the Ge2Sb2Te5 has an increasingly dominant effect on the material’s ability to change phase, and a profound increase in the crystallization temperature is observed when the Ge2Sb2Te...

Atomic and electronic structures of amorphous Ge(2)Sb(2)Te(5); melt-quenched versus ideal glasses.

To investigate an amorphous structure of Ge(2)Sb(2)Te(5) that satisfies the 8-N rule (so-called 'ideal glass'), we perform alternative melt-quench simulations on Si(2)As(2)Se(5) and replace atoms in the final structure with Ge-Sb-Te. The resulting structures have salient features of the 8-N rule such as the tetrahedral configuration for all Ge atoms and the localized Te lone pairs at the valenc...

Optical properties and phase - change transition in Ge 2 Sb 2 Te 5 flash evaporated thin films studied by temperature dependent spectroscopic ellipsometry

We studied the optical properties of as-prepared (amorphous) and thermally crystallized (fcc) flash evaporated Ge2Sb2Te5 thin films using variable angle spectroscopic ellipsometry in the photon energy range 0.54 4.13 eV. We employed Tauc-Lorentz model (TL) and CodyLorentz model (CL) for amorphous phase and Tauc-Lorentz model with one additional Gaussian oscillator for fcc phase data analysis. T...