TY - JOUR

T1 - Unraveling the Atomic Structure of Bulk Binary Ga-Te Glasses with Surprising Nanotectonic Features for Phase-Change Memory Applications

AU - Bokova, Maria

AU - Tverjanovich, Andrey

AU - Benmore, Chris J.

AU - Fontanari, Daniele

AU - Sokolov, Anton

AU - Khomenko, Maxim

AU - Kassem, Mohammad

AU - Ozheredov, Ilya

AU - Bychkov, Eugene

N1 - Funding Information: This work was supported by the Ministry of Science and Higher Education under Agreement no. 075-15-2019-1950, state assignment FSRC “Crystallography and Photonics”, Russian Academy of Sciences. The work at the Advanced Photon Source, Argonne National Laboratory, was supported in part by the Office of Basic Energy Sciences, US Department of Energy, under Contract no. DE-AC02-06CH1135. The XRD measurements in part were carried out in the resource center of St. Petersburg State University, “Center for X-ray Diffraction Studies”. The FPMD simulations were carried out using the HPC computing resources at Lomonosov Moscow State University and at the ILIT RAS in Shatura (Moscow Region). This work was also granted access to the HPC resources of IDRIS (France) under the allocation 2020-A0090910639 made by Grand Equipement National de Calcul Intensif (GENCI) and to use the CALCULCO computing platform, supported by Service COmmun du Système d’Information de l’Université du Littoral Côte d’Opale (SCoSI/ULCO). Publisher Copyright: © 2021 American Chemical Society. All rights reserved.

PY - 2021/8/11

Y1 - 2021/8/11

N2 - Binary Ge-Te and ternary Ge-Sb-Te systems belong to flagship phase-change materials (PCMs) and are used in nonvolatile memory applications and neuromorphic computing. The working temperatures of these PCMs are limited by low-T glass transition and crystallization phenomena. Promising high-T PCMs may include gallium tellurides; however, the atomic structure and transformation processes for amorphous Ga-Te binaries are simply missing. Using high-energy X-ray diffraction and Raman spectroscopy supported by first-principles simulations, we elucidate the short- and intermediate-range order in bulk glassy GaxTe1-x, 0.17 ≤ x ≤ 0.25, following their thermal, electric, and optical properties, revealing a semiconductor-metal transition above melting. We also show that a phase change in binary Ga-Te is characterized by a very unusual nanotectonic compression with the high internal transition pressure reaching 4-8 GPa, which appears to be beneficial for PCM applications increasing optical and electrical contrast between the SET and RESET states and decreasing power consumption.

AB - Binary Ge-Te and ternary Ge-Sb-Te systems belong to flagship phase-change materials (PCMs) and are used in nonvolatile memory applications and neuromorphic computing. The working temperatures of these PCMs are limited by low-T glass transition and crystallization phenomena. Promising high-T PCMs may include gallium tellurides; however, the atomic structure and transformation processes for amorphous Ga-Te binaries are simply missing. Using high-energy X-ray diffraction and Raman spectroscopy supported by first-principles simulations, we elucidate the short- and intermediate-range order in bulk glassy GaxTe1-x, 0.17 ≤ x ≤ 0.25, following their thermal, electric, and optical properties, revealing a semiconductor-metal transition above melting. We also show that a phase change in binary Ga-Te is characterized by a very unusual nanotectonic compression with the high internal transition pressure reaching 4-8 GPa, which appears to be beneficial for PCM applications increasing optical and electrical contrast between the SET and RESET states and decreasing power consumption.

KW - first-principles simulations

KW - Ga-Te binaries

KW - nanotectonic compression

KW - optical and electronic properties

KW - phase-change materials

KW - Raman spectroscopy

KW - X-ray diffraction

KW - THIN-FILMS

KW - CRYSTALLIZATION

KW - CRYSTAL-STRUCTURE

KW - RAMAN-SPECTROSCOPY

KW - HIGH-PRESSURE PHASE

KW - NEUTRON-DIFFRACTION

KW - OPTICAL-PROPERTIES

KW - RANGE-ORDER

KW - X-RAY

KW - REFRACTIVE-INDEX

UR - http://www.scopus.com/inward/record.url?scp=85112548189&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/fc3598f4-e847-327d-bc77-6db1c2e64a65/

U2 - 10.1021/acsami.1c09070

DO - 10.1021/acsami.1c09070

M3 - Article

AN - SCOPUS:85112548189

VL - 13

SP - 37353

EP - 37369

JO - ACS applied materials & interfaces

JF - ACS applied materials & interfaces

SN - 1944-8244

IS - 31

ER -