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Effects of Ge/Sb Intermixing on the Local Structures and Optical Properties of GeTe–Sb2Te3 Superlattice

  • Gang Han
  • Furong LiuEmail author
Conference paper
  • 266 Downloads
Part of the The Minerals, Metals & Materials Series book series (MMMS)

Abstract

GeTe–Sb2Te3-based superlattice (GST-SL) is a new phase change film prepared with alternative GeTe and Sb2Te3 layers, known as interfacial phase-change material, showing strongly improved switching properties. However, the recent experiments showed that Ge/Sb atomic intermixing was hardly to be avoided and would influence the phase change process. In this paper, the effects of Ge/Sb atomic intermixing on the local structure and phase change mechanism were investigated by first-principles simulations. The free energy evolution with temperatures indicated that Ge/Sb intermixing is helpful for phase change. The bond analysis and local order parameter showed that no obvious structure changes happened when lower than 1200 K, and there were almost no fourfold Ge-tetrahedral structures even when quenched from 1500 K, different from the traditional GST materials. The Ge/Sb intermixing and its ratios can not only influence the structural transition, but also play a vital role on the optical properties. These findings enrich a deep understanding of Ge/Sb intermixing on GST-SL phase changes.

Keywords

Intermixing First-principles simulation Local structure Optical properties Phase change mechanism 

Notes

Acknowledgements

This work is supported by the Beijing Natural Science Foundation-Municipal Education Committee Joint Funding Project (KZ201910005004).

Conflicts of Interest

The authors declare no competing financial interest.

References

  1. 1.
    Wuttig M, Yamada N (2007) Phase-change materials for rewriteable data storage. Nat Mater 6:824–832CrossRefGoogle Scholar
  2. 2.
    Burr GW, Breitwisch MJ, Franceschini M et al (2010) Phase change memory technology. J Vac Sci Technol B 28:223–262CrossRefGoogle Scholar
  3. 3.
    Simpson RE, Fons P, Kolobov AV et al (2011) Interfacial phase-change memory. Nat Nanotechnol 6:501–505CrossRefGoogle Scholar
  4. 4.
    Chong TC, Shi LP, Wei XQ et al (2008) Crystalline amorphous semiconductor superlattice. Phys Rev Lett 100:136101CrossRefGoogle Scholar
  5. 5.
    Tominaga J, Simpson RE, Fons P et al (2011) Electrical-field induced giant magnetoresistivity in (non-magnetic) phase change films. Appl Phys Lett 99:152105CrossRefGoogle Scholar
  6. 6.
    Tominaga J, Kolobov AV, Fons P et al (2015) Giant multiferroic effects in topological GeTe–Sb2Te3 superlattices. Sci Technol Adv Mater 16:014402CrossRefGoogle Scholar
  7. 7.
    Bang D, Awano H, Tominaga J et al (2014) Mirror-symmetric magneto-optical Kerr rotation using visible light in [(GeTe)2(Sb2Te3)1]n topological superlattices. Sci Rep 4:5727CrossRefGoogle Scholar
  8. 8.
    Yu X, Robertson J (2015) Modeling of switching mechanism in GeSbTe chalcogenide superlattices. Sci Rep 5:12612CrossRefGoogle Scholar
  9. 9.
    Kolobov AV, Fons PY et al (2017) Atomic reconfiguration of van der Waals gaps as the key to switching in GeTe/Sb2Te3 superlattices. ACS Omega 2:6223–6232Google Scholar
  10. 10.
    Momand J, Wang R, Boschker JE et al (2017) Dynamic reconfiguration of van der Waals gaps within GeTe–Sb2Te3 based superlattices. Nanoscale 9:8774–8780CrossRefGoogle Scholar
  11. 11.
    Momand J, Wang R, Boschker JE et al (2015) Interface formation of two- and three-dimensionally bonded materials in the case of GeTe–Sb2Te3 superlattices Nanoscale 7, 19136–19143Google Scholar
  12. 12.
    Lotnyk A, Hilmi I, Ross U et al (2018) Van der Waals interfacial bonding and intermixing in GeTe–Sb2Te3-based superlattices. Nano Res 11:1676–1686CrossRefGoogle Scholar
  13. 13.
    Momanda J, Lange FRL, Wang R et al (2016) Atomic stacking and van-der-Waals bonding in GeTe–Sb2Te3 superlattices. J Mater Res 31:3115–3124CrossRefGoogle Scholar
  14. 14.
    Li XB, Chen NK, Wang XP et al (2018) Phase-change superlattice materials toward low power consumption and high density data storage: microscopic picture, working principles, and optimization. Adv Funct Mater 28:1803380CrossRefGoogle Scholar
  15. 15.
    Tominaga J, Kolobov AV, Fons P et al (2014) Ferroelectric order control of the dirac-semimetal phase in GeTe–Sb2Te3 superlattices. Adv Mater Interfaces 1:1300027CrossRefGoogle Scholar
  16. 16.
    Ohyanagi T, Kitamura M, Araidai M et al (2014) GeTe sequences in superlattice phase change memories and their electrical characteristics. Appl Phys Lett 104:252106CrossRefGoogle Scholar
  17. 17.
    Kresse G, Furthmuller J (1996) Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comp Mater Sci 6:15–50CrossRefGoogle Scholar
  18. 18.
    Kresse G, Hafner J (1993) Ab initio molecular dynamics for liquid metals. Phys Rev B 47:558–561CrossRefGoogle Scholar
  19. 19.
    Blöchl PE (1994) Projector augmented-wave method. Phys Rev B 50:17953–17979CrossRefGoogle Scholar
  20. 20.
    Perdew JP, Burke K, Ernzerhof M (1996) Generalized gradient approximation made simple. Phys Rev Lett 78:3865–3868CrossRefGoogle Scholar
  21. 21.
    Kresse G, Joubert D (1999) From ultrasoft pseudopotentials to the projector augmented-wave method. Phys Rev B 59:1758–1775CrossRefGoogle Scholar
  22. 22.
    Mio AM, Privitera SM, Bragaglia V et al (2017) Chemical and structural arrangement of the trigonal phase in GeSbTe thin films. Nanotechnology 28:065706CrossRefGoogle Scholar
  23. 23.
    Casarin B, Caretta A, Momand J et al (2016) Revisiting the local structure in Ge–Sb–Te based chalcogenide superlattices. Sci Rep 6:22353CrossRefGoogle Scholar
  24. 24.
    Kowalczyk P, Hippert F, Bernier N et al (2018) Impact of stoichiometry on the structure of van der Waals layered GeTe/Sb2Te3 superlattices used in interfacial phase-change memory (iPCM) devices. Small 14:1704514CrossRefGoogle Scholar
  25. 25.
    Da Silva JLF, Walsh A, Lee H (2008) Insights into the structure of the stable and metastable (GeTe)m(Sb2Te3)n compounds. Phy Rev B 78:224111Google Scholar
  26. 26.
    Nosé S (1984) A unified formulation of the constant temperature molecular dynamics methods. J Chem Phys 81:511–519CrossRefGoogle Scholar
  27. 27.
    Jóvári P, Kaban I, Steiner J et al (2007) ‘Wrong bonds’ in sputtered amorphous Ge2Sb2Te5. J Phys: Condens Matter 19:335212Google Scholar
  28. 28.
    Akola J, Jones RO (2008) Density functional study of amorphous, liquid and crystalline Ge2Sb2Te5: homopolar bonds and/or AB alternation? J Phys Condens Matter 20:465103CrossRefGoogle Scholar
  29. 29.
    Caravati S, Bernasconi M, Kühne TD et al (2007) Coexistence of tetrahedral- and octahedral-like sites in amorphous phase change materials. Appl Phys Lett 91:171906CrossRefGoogle Scholar
  30. 30.
    Errington JR, Debenedetti PG (2001) Relationship between structural order and the anomalies of liquid water. Nature 409:318–321CrossRefGoogle Scholar
  31. 31.
    Deringer VL, Zhang W, Lumeij M et al (2014) Bonding nature of local structural motifs in amorphous GeTe. Angew Chem Int Ed 53:10817–10820CrossRefGoogle Scholar
  32. 32.
    Zhang W, Deringer VL, Dronskowski R et al (2015) Density-functional theory guided advances in phase-change materials and memories. MRS Bull 40:856–869CrossRefGoogle Scholar
  33. 33.
    Wang XP, Li XB, Chen NK et al (2017) Element-specific amorphization of vacancy-ordered GeSbTe for ternary-state phase change memory. Acta Mater 136:242–248CrossRefGoogle Scholar
  34. 34.
    Kolobov AV, Fons P, Frenkel AI et al (2004) Understanding the phase-change mechanism of rewritable optical media. Nat Mater 3:703–708CrossRefGoogle Scholar
  35. 35.
    Qiao C, Guo YR, Wang JJ et al (2019) The local structural differences in amorphous Ge–Sb–Te alloys. J Alloys Compd 774:748–757CrossRefGoogle Scholar
  36. 36.
    Krbal M, Kolobov AV, Fons P et al (2011) Intrinsic complexity of the melt-quenched amorphous Ge2Sb2Te5 memory alloy. Phy Rev B 83:054203CrossRefGoogle Scholar
  37. 37.
    Meng Y, Behera JK, Wen S et al (2018) Ultrafast multilevel optical tuning with CSb2Te3 thin films. Adv Opt Mater 6:1800360CrossRefGoogle Scholar
  38. 38.
    Xu M, Cheng YQ, Sheng HW et al (2009) Nature of atomic bonding and atomic structure in the phase-change Ge2Sb2Te5 glass. Phys Rev Lett 103:195502Google Scholar

Copyright information

© The Minerals, Metals & Materials Society 2020

Authors and Affiliations

  1. 1.Institute of Laser Engineering, Beijing University of TechnologyBeijingChina
  2. 2.Beijing Engineering Research Center of Applied Laser TechnologyBeijing University of TechnologyBeijingChina

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