TY - JOUR
T1 - Multistates and Polyamorphism in Phase-Change K2Sb8Se13
AU - Islam, Saiful M.
AU - Peng, Lintao
AU - Zeng, Li
AU - Malliakas, Christos D.
AU - Chung, Duck Young
AU - Buchholz, D. Bruce
AU - Chasapis, Thomas
AU - Li, Ran
AU - Chrissafis, Konstantinos
AU - Medvedeva, Julia E.
AU - Trimarchi, Giancarlo G.
AU - Grayson, Matthew
AU - Marks, Tobin J
AU - Bedzyk, Michael J.
AU - Chang, Robert P. H.
AU - Dravid, Vinayak P.
AU - Kanatzidis, Mercouri G
PY - 2018/7/25
Y1 - 2018/7/25
N2 - 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 °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 °C and 1 atm. All three states of K2Sb8Se13 exhibit distinct optical bandgaps, Eg = 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.
AB - 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 °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 °C and 1 atm. All three states of K2Sb8Se13 exhibit distinct optical bandgaps, Eg = 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.
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U2 - 10.1021/jacs.8b05542
DO - 10.1021/jacs.8b05542
M3 - Article
C2 - 29956935
AN - SCOPUS:85049411864
VL - 140
SP - 9261
EP - 9268
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 29
ER -