Multistates and Polyamorphism in Phase-Change K₂Sb₈Se₁₃

Journal Article · Tue Jun 19 00:00:00 EDT 2018 · Journal of the American Chemical Society

DOI:https://doi.org/10.1021/jacs.8b05542· OSTI ID:1488379

Islam, Saiful M.  ^[1]; Peng, Lintao ^[2]; Zeng, Li  ^[2]; Malliakas, Christos D.  ^[1]; Chung, Duck Young ^[3]; Buchholz, D. Bruce ^[4]; Chasapis, Thomas ^[1]; Li, Ran ^[4]; Chrissafis, Konstantinos ^[5]; Medvedeva, Julia E. ^[6]; Trimarchi, Giancarlo G. ^[7]; Grayson, Matthew ^[8]; Marks, Tobin J.  ^[9]; Bedzyk, Michael J.  ^[10]; Chang, Robert P. H. ^[4]; Dravid, Vinayak P.  ^[4]; Kanatzidis, Mercouri G.  ^[11]

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1. Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
2. Applied Physics Graduate Program, Northwestern University, Evanston, Illinois 60208, United States
3. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
4. Department of Material Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
5. Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece
6. Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409-0640, United States
7. Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, United States
8. Applied Physics Graduate Program, Northwestern University, Evanston, Illinois 60208, United States; Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, Illinois 60208, United States
9. Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States; Applied Physics Graduate Program, Northwestern University, Evanston, Illinois 60208, United States; Department of Material Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
10. Applied Physics Graduate Program, Northwestern University, Evanston, Illinois 60208, United States; Department of Material Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States; Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, United States
11. Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States; Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States

The phase-change (PC) materials in the majority of optical data storage media in use today exhibit a fast, reversible crystal -> amorphous phase transition that allows them to be switched between on (1) and off (0) binary states. Solid-state inorganic materials with this property are relatively common, but those exhibiting an amorphous -> amorphous transition called polyamorphism are exceptionally rare. K₂Sb₈Se₁₃ (KSS) reported here is the first example of a material that has both amorphous -> amorphous polyamorphic transition and amorphous -> crystal transition at easily accessible temperatures (227 and 263 degrees C, respectively). The transitions are associated with the atomic coordinative preferences of the atoms, and all three states of K₂Sb₈Se₁₃ are stable in air at 25 degrees C and 1 atm. All three states of K₂Sb₈Se₁₃ exhibit distinct optical bandgaps, E-g = 1.25, 1.0, and 0.74 eV, for the amorphous-II, amorphous-I, and crystalline versions, respectively. The room-temperature electrical conductivity increases by more than 2 orders of magnitude from amorphous-I to -II and by another 2 orders of magnitude from amorphous-II to the crystalline state. This extraordinary behavior suggests that a new class of materials exist which could provide multistate level systems to enable higher-order computing logic circuits, reconfigurable logic devices, and optical switches.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division; National Science Foundation (NSF); W.M. Keck Foundation; Dow Chemical Company; USDOE Office of Science - National Energy Research Scientific Computing Center (NERSC)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 1488379
• Journal Information: Journal of the American Chemical Society, Vol. 140, Issue 29; ISSN 0002-7863
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

amorphous-amorphous transition
chalcogenides
crystal-amorphous transition
phase change materials
phase change memory
polyamorphism