skip to main content

DOE PAGESDOE PAGES

Title: Sub-nanometre resolution of atomic motion during electronic excitation in phase-change materials

Phase-change materials based on Ge-Sb-Te alloys are widely used in industrial applications such as nonvolatile memories, but reaction pathways for crystalline-to-amorphous phase-change on picosecond timescales remain unknown. Femtosecond laser excitation and an ultrashort x-ray probe is used to show the temporal separation of electronic and thermal effects in a long-lived (>100 ps) transient metastable state of Ge2Sb2Te5 with muted interatomic interaction induced by a weakening of resonant bonding. Due to a specific electronic state, the lattice undergoes a reversible nondestructive modification over a nanoscale region, remaining cold for 4 ps. An independent time-resolved x-ray absorption fine structure experiment confirms the existence of an intermediate state with disordered bonds. Furthermore, this newly unveiled effect allows the utilization of non-thermal ultra-fast pathways enabling artificial manipulation of the switching process, ultimately leading to a redefined speed limit, and improved energy efficiency and reliability of phase-change memory technologies.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [3] ;  [7] ;  [7] ;  [7] ;  [7] ;  [8] ;  [9] ;  [8] ;  [9] ;  [8] ;  [10] ;  [11] ;  [12]
  1. National Inst. of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); RIKEN SPring-8 Center, Kouto (Japan)
  2. National Inst. of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); RIKEN SPring-8 Center, Kouto (Japan); Japan Synchrotron Radiation Research Institute, Kouto (Japan)
  3. National Inst. of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan)
  4. Univ. of Tsukuba (Japan)
  5. Hirosaki Univ. (Japan)
  6. National Inst. of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); Japan Synchrotron Radiation Research Institute, Kouto (Japan)
  7. Paul-Drude-Institut fur Festkorperelektronik, Berlin (Germany)
  8. RIKEN SPring-8 Center, Kouto (Japan)
  9. Japan Synchrotron Radiation Research Institute, Kouto (Japan)
  10. The Barcelona Institute of Science and Technology (BIST), Barcelona (Spain)
  11. Argonne National Lab. (ANL), Argonne, IL (United States). X-ray Science Division
  12. National Inst. of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); Univ. of Tsukuba (Japan); RIKEN SPring-8 Center, Kouto (Japan)
Publication Date:
OSTI Identifier:
1253632
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 6; Journal ID: ISSN 2045-2322
Publisher:
Nature Publishing Group
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY condensed-matter physics; phase transition and critical phenomena; surfaces, interfaces and thin films