We generated models of the amorphous phase of Sb-rich GeSbTe phase change alloys by quenching from the melt within density functional molecular dynamics. We considered the two compositions Ge1Sb1Te1 and Ge2Sb4Te5. Comparison with previous results on the most studied Ge2Sb2Te5 allowed us to draw some conclusions on the dependence of the structural properties of the amorphous phase on the alloy composition. Vibrational and electronic properties were also scrutinized. Phonons at high frequencies above 200 cm-1 are localized in tetrahedra around Ge atoms in Sb-rich compounds as well as in Ge2Sb2Te5. All compounds are semiconducting in the amorphous phase, with a band gap in the range 0.7–1.0 eV.

Gabardi, S., Caravati, S., Bernasconi, M., Parrinello, M. (2012). Density functional simulations of Sb-rich GeSbTe phase change alloys. JOURNAL OF PHYSICS. CONDENSED MATTER, 24(38), 385803 [10.1088/0953-8984/24/38/385803].

Density functional simulations of Sb-rich GeSbTe phase change alloys

GABARDI, SILVIA;BERNASCONI, MARCO;
2012

Abstract

We generated models of the amorphous phase of Sb-rich GeSbTe phase change alloys by quenching from the melt within density functional molecular dynamics. We considered the two compositions Ge1Sb1Te1 and Ge2Sb4Te5. Comparison with previous results on the most studied Ge2Sb2Te5 allowed us to draw some conclusions on the dependence of the structural properties of the amorphous phase on the alloy composition. Vibrational and electronic properties were also scrutinized. Phonons at high frequencies above 200 cm-1 are localized in tetrahedra around Ge atoms in Sb-rich compounds as well as in Ge2Sb2Te5. All compounds are semiconducting in the amorphous phase, with a band gap in the range 0.7–1.0 eV.
Articolo in rivista - Articolo scientifico
Density functional simulations, glasses, phase change materials
English
2012
24
38
385803
none
Gabardi, S., Caravati, S., Bernasconi, M., Parrinello, M. (2012). Density functional simulations of Sb-rich GeSbTe phase change alloys. JOURNAL OF PHYSICS. CONDENSED MATTER, 24(38), 385803 [10.1088/0953-8984/24/38/385803].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/37346
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