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Nano Research 2016, 9(11): 3453-3462 https://doi.org/10.1007/s12274-016-1221-8
Research Article | Issue | Published: 31 August 2016

Direct observation of metastable face-centered cubic Sb2Te3 crystal

Show Author's Information Yonghui Zheng1,§,  Mengjiao Xia2,§,  Yan Cheng1( ),  Feng Rao1( ),  Keyuan Ding1,  Weili Liu1,  Yu Jia2,  Zhitang Song1( ),  Songlin Feng1
State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Micro-system and Information TechnologyChinese Academy of SciencesShanghai200050China
International Laboratory of Quantum Functional Materials of HenanSchool of Physics and EngineeringZhengzhou UniversityZhengzhou450001China

§These authors contributed equally to this work.

Keywords:
phase change memory, Sb2Te3, face-centered cubic, TEM, ab initio theoretical simulation
Cite this article:
Zheng Y, Xia M, Cheng Y, et al. Direct observation of metastable face-centered cubic Sb2Te3 crystal. Nano Research, 2016, 9(11): 3453-3462. https://doi.org/10.1007/s12274-016-1221-8
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Abstract Full text Electronic supplementary material About this article

Although phase change memory technology has developed drastically in the past two decades, the cognition of the key switching materials still ignores an important member, the face-centered cubic Sb2Te3. Apart from the well-known equilibrium hexagonal Sb2Te3 crystal, we prove the metastable face-centered cubic Sb2Te3 phase does exist. Such a metastable crystal contains a large concentration of vacancies randomly occupying the cationic lattice sites. The face-centered cubic to hexagonal phase transformation of Sb2Te3, accompanied by vacancy aggregation, occurs at a quite lower temperature compared to that of Ge2Sb2Te5 alloy. We prove that the covalent-like bonds prevail in the metastable Sb2Te3 crystal, deviating from the ideal resonant features. If a proper doping technique is adopted, the metastable Sb2Te3 phase could be promising for realizing reversibly swift and low-energy phase change memory applications. Our study may offer a new insight into commercialized Ge–Sb–Te systems and help in the design of novel phase change materials to boost the performances of the phase change memory device.


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Electronic supplementary material
About this article

Direct observation of metastable face-centered cubic Sb2Te3 crystal

Show Author's information Yonghui Zheng1,§, Mengjiao Xia2,§, Yan Cheng1( ), Feng Rao1( ), Keyuan Ding1, Weili Liu1, Yu Jia2, Zhitang Song1( ), Songlin Feng1
State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Micro-system and Information TechnologyChinese Academy of SciencesShanghai200050China
International Laboratory of Quantum Functional Materials of HenanSchool of Physics and EngineeringZhengzhou UniversityZhengzhou450001China

§These authors contributed equally to this work.

Abstract

Although phase change memory technology has developed drastically in the past two decades, the cognition of the key switching materials still ignores an important member, the face-centered cubic Sb2Te3. Apart from the well-known equilibrium hexagonal Sb2Te3 crystal, we prove the metastable face-centered cubic Sb2Te3 phase does exist. Such a metastable crystal contains a large concentration of vacancies randomly occupying the cationic lattice sites. The face-centered cubic to hexagonal phase transformation of Sb2Te3, accompanied by vacancy aggregation, occurs at a quite lower temperature compared to that of Ge2Sb2Te5 alloy. We prove that the covalent-like bonds prevail in the metastable Sb2Te3 crystal, deviating from the ideal resonant features. If a proper doping technique is adopted, the metastable Sb2Te3 phase could be promising for realizing reversibly swift and low-energy phase change memory applications. Our study may offer a new insight into commercialized Ge–Sb–Te systems and help in the design of novel phase change materials to boost the performances of the phase change memory device.

Keywords: phase change memory, Sb2Te3, face-centered cubic, TEM, ab initio theoretical simulation

References(36)

1

Wong, H. -S. P.; Salahuddin, S. Memory leads the way to better computing. Nat. Nanotechnol. 2015, 10, 191–194.
DOI Google Scholar
2

Choi, Y.; Song, I.; Park, M. H.; Chung, H.; Chang, S.; Cho, B.; Kim, J.; Oh, Y.; Kwon, D.; Sunwoo, J. et al. A 20nm 1.8V 8Gb PRAM with 40MB/s program bandwidth. In Proceedings of the 2012 IEEE Solid-State Circuits Conference, San Francisco, CA, 2012, pp 46–48.
DOI Google Scholar
3

Villa, C.; Mills, D.; Barkley, G.; Giduturi, H.; Schippers, S.; Vimercati, D. A 45nm 1Gb 1.8V phase-change memory. In Proceedings of the 2010 IEEE Solid-State Circuits Conference, San Francisco, CA, 2010, pp 270−271.
Google Scholar
4

Wuttig, M. Phase-change materials: Towards a universal memory? Nat. Mater. 2005, 4, 265–266.
DOI Google Scholar
5

Atwood, G. Phase-change materials for electronic memories. Science 2008, 321, 210–211.
DOI Google Scholar
6

Yamada, N.; Ohno, E.; Nishiuchi, K.; Akahira, N.; Takao, M. Rapid-phase transitions of GeTe-Sb2Te3 pseudobinary amorphous thin films for an optical disk memory. J. Appl. Phys. 1991, 69, 2849–2856.
DOI Google Scholar
7

Friedrich, I.; Weidenhof, V.; Njoroge, W.; Franz, P.; Wuttig, M. Structural transformations of Ge2Sb2Te5 films studied by electrical resistance measurements. J. Appl. Phys. 2000, 87, 4130–4134.
DOI Google Scholar
8

Cheng, H. Y.; Hsu, T. H.; Raoux, S.; Wu, J. Y.; Du, P. Y.; Breitwisch, M.; Zhu, Y.; Lai, E. K.; Joseph, E.; Mittal, S. et al. A high performance phase change memory with fast switching speed and high temperature retention by engineering the GexSbyTez phase change material. In Proceedings of the 2011 IEEE International Electron Devices Meeting, Washington, DC, 2011, pp 3.4.1–3.4.4.
DOI Google Scholar
9

Kolobov, A. V.; Fons, P.; Frenkel, A. I.; Ankudinov, A. L.; Tominaga, J.; Uruga, T. Understanding the phase-change mechanism of rewritable optical media. Nat. Mater. 2004, 3, 703–708.
DOI Google Scholar
10

Xu, M.; Cheng, Y. Q.; Sheng, H. W.; Ma. E. Nature of atomic bonding and atomic structure in the phase-change Ge2Sb2Te5 glass. Phys. Rev. Lett. 2009, 103, 195502.
DOI Google Scholar
11

Shportko, K.; Kremers, S.; Woda, M.; Lencer, D.; Robertson, J.; Wuttig, M. Resonant bonding in crystalline phase-change materials. Nat. Mater. 2008, 7, 653–658.
DOI Google Scholar
12

Lencer, D.; Salinga, M.; Grabowski, B.; Hickel, T.; Neugebauer, J.; Wuttig, M. A map for phase-change materials. Nat. Mater. 2008, 7, 972–977.
DOI Google Scholar
13

Kolobov, A. V.; Fons, P.; Tominaga, J.; Hase, M. Excitationassisted disordering of GeTe and related solids with resonant bonding. J. Phys. Chem. C 2014, 118, 10248–10253.
DOI Google Scholar
14

Kolobov, A. V.; Fons, P.; Tominaga, J.; Frenkel, A. I.; Ankudinov, A. L.; Yannopoulos, S. N.; Andrikopoulos, K. S.; Uruga, T. Why phase-change media are fast and stable: A new approach to an old problem. Jpn. J. Appl. Phys. 2005, 44, 3345–3349.
DOI Google Scholar
15

Sun, Z. M.; Zhou, J.; Mao, H. K.; Ahuja, R. Peierls distortion mediated reversible phase transition in GeTe under pressure. Proc. Natl. Acad. Sci. USA 2012, 109, 5948–5952.
DOI Google Scholar
16

Kolobov, A. V.; Fons, P.; Tominaga, J.; Ovshinsky, S. R. Vacancy-mediated three-center four-electron bonds in GeTe-Sb2Te3 phase-change memory alloys. Phys. Rev. B 2013, 87, 165206.
DOI Google Scholar
17

Da Silva, J. L. F.; Walsh, A.; Lee, H. Insights into the structure of the stable and metastable (GeTe)m(Sb2Te3)n compounds. Phys. Rev. B 2008, 78, 224111.
DOI Google Scholar
18

Zhang, W.; Thiess, A.; Zalden, P.; Zeller, R.; Dederichs, P. H.; Raty, J. -Y.; Wuttig, M.; Blügel, S.; Mazzarello, R. Role of vacancies in metal–insulator transitions of crystalline phasechange materials. Nat. Mater. 2012, 11, 952–956.
DOI Google Scholar
19

Yin, Y.; Sone, H.; Hosaka, S. Characterization of nitrogendoped Sb2Te3 films and their application to phase-change memory. J. Appl. Phys. 2007, 102, 064503.
DOI Google Scholar
20

Zhu, M.; Xia, M. J.; Rao, F.; Li, X. B.; Wu, L. C.; Ji, X. L.; Lv, S. L.; Song, Z. T.; Feng, S. L.; Sun, H. B. et al. One order of magnitude faster phase change at reduced power in Ti-Sb-Te. Nat. Commun. 2014, 5, 4086.
DOI Google Scholar
21

Williams, D. B.; Carter, C. B. Transmission Electron Microscopy: A Textbook for Materials Science, 2nd ed.; Springer: Berlin, 2009.
22

Waldecker, L.; Miller, T. A.; Rudé, M.; Bertoni, R.; Osmond, J.; Pruneri, V.; Simpson, R. E.; Ernstorfer, R.; Wall, S. Time-domain separation of optical properties from structural transitions in resonantly bonded materials. Nat. Mater. 2015, 14, 991–995.
DOI Google Scholar
23

Yu, J. L.; Liu, B.; Zhang, T.; Song, Z. T.; Feng, S. L.; Chen, B. Effects of Ge doping on the properties of Sb2Te3 phasechange thin films. Appl. Surf. Sci. 2007, 253, 6125–6129.
DOI Google Scholar
24

Spence, J. C. H. High-Resolution Electron Microscopy, 3rd ed.; Oxford University Press: New York, 2003.
25

Sun, Z. M.; Zhou, J.; Ahuja, R. Structure of phase change materials for data storage. Phys. Rev. Lett. 2006, 96, 055507.
DOI Google Scholar
26

Caravati, S.; Bernasconi, M.; Parrinello, M. First-principles study of liquid and amorphous Sb2Te3. Phys. Rev. B 2010, 81, 014201.
DOI Google Scholar
27

Kolobov, A. V.; Fons, P.; Tominaga, J. p-type conductivity of GeTe: The role of lone-pair electrons. Phys. Status Solidi B 2012, 249, 1902–1906.
DOI Google Scholar
28

Kastner, M.; Adler, D.; Fritzsche, H. Valence-alternation model for localized gap states in lone-pair semiconductors. Phys. Rev. Lett. 1976, 37, 1504–1507.
DOI Google Scholar
29

Sun, Z. M.; Zhou, J.; Blomqvist, A.; Johansson, B.; Ahuja, R. Formation of large voids in the amorphous phase-change memory Ge2Sb2Te5 alloy. Phys. Rev. Lett. 2009, 102, 075504.
DOI Google Scholar
30

Rao, F.; Song, Z. T.; Ren, K.; Zhou, X. L.; Cheng, Y.; Wu, L. C.; Liu, B. Si–Sb–Te materials for phase change memory applications. Nanotechnology 2011, 22, 145702.
DOI Google Scholar
31

Zhou, X. L.; Xia, M. J.; Rao, F.; Wu, L. C.; Li, X. B.; Song, Z. T.; Feng, S. L.; Sun, H. B. Understanding phase-change behaviors of carbon-doped Ge2Sb2Te5 for phase-change memory application. ACS Appl. Mater. Interfaces 2014, 6, 14207–14214.
DOI Google Scholar
32

Kooi, B. J.; Groot, W. M. G.; De Hosson, J. Th. M. In situ transmission electron microscopy study of the crystallization of Ge2Sb2Te5. J. Appl. Phys. 2004, 95, 924–932.
DOI Google Scholar
33

Hohenberg, P.; Kohn, W. Inhomogeneous electron gas. Phys. Rev. 1964, 136, B864–B871.
DOI Google Scholar
34

Kresse, G.; Hafner, J. Ab initio molecular dynamics for liquid metals. Phys. Rev. B 1993, 47, 558–561.
DOI Google Scholar
35

Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 1994, 50, 17953–17979.
DOI Google Scholar
36

Perdew, J. P.; Burke, K.; Ernzerhof, M.; Generalized gradient approximation made simple. Phys. Rev. Lett. 1996, 77, 3865–386.
DOI Google Scholar
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Publication history
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Acknowledgements

Publication history

Received: 08 April 2016
Revised: 12 July 2016
Accepted: 15 July 2016
Published: 31 August 2016
Issue date: November 2016

Copyright

© Tsinghua University Press and Springer-Verlag Berlin Heidelberg 2016

Acknowledgements

Acknowledgements

This work was supported by the Strategic Priority Research Program of Chinese Academy of Sciences (No.XDA09020402), National Integrate Circuit Research Program of China (No. 2009ZX02023-003), National Natural Science Foundation of China (Nos. 61076121, 61176122, 61106001, 61261160500, and 61376006), Science and Technology Council of Shanghai (Nos. 13ZR1447200 and 13DZ2295700). The supercomputer time was provided by the National Supercomputer Center in Tianjin, and the calculations were performed on TianHe-1 (A).

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