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Title: Reversible migration of silver on memorized pathways in Ag-Ge{sub 40}S{sub 60} films

Reversible and reproducible formation and dissolution of silver conductive filaments are studied in Ag-photodoped thin-film Ge{sub 40}S{sub 60} subjected to electric fields. A tip-planar geometry is employed, where a conductive-atomic-force microscopy tip is the tip electrode and a silver patch is the planar electrode. We highlight an inherent “memory” effect in the amorphous chalcogenide solid-state electrolyte, in which particular silver-ion migration pathways are preserved “memorized” during writing and erasing cycles. The “memorized” pathways reflect structural changes in the photodoped chalcogenide film. Structural changes due to silver photodoping, and electrically-induced structural changes arising from silver migration, are elucidated using Raman spectroscopy. Conductive filament formation, dissolution, and electron (reduction) efficiency in a lateral device geometry are related to operation of the nano-ionic Programmable Metallization Cell memory and to newly emerging chalcogenide-based lateral geometry MEMS technologies. The methods in this work can also be used for qualitative multi-parameter sampling of metal/amorphous-chalcogenide combinations, characterizing the growth/dissolution rates, retention and endurance of fractal conductive filaments, with the aim of optimizing devices.
Authors:
;  [1] ;  [2] ;  [3] ;  [4]
  1. Department of Materials Science & Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom)
  2. (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)
  3. School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, Arizona 85287-6206 (United States)
  4. Foundation of Research and Technology Hellas - Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Patras, P. O. Box 1414 (Greece)
Publication Date:
OSTI Identifier:
22493947
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 7; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ATOMIC FORCE MICROSCOPY; DISSOLUTION; ELECTRIC CONDUCTIVITY; ELECTRIC FIELDS; ELECTROLYTES; ELECTRONS; FILAMENTS; FRACTALS; GERMANIUM SULFIDES; MEMS; RAMAN SPECTROSCOPY; REDUCTION; RETENTION; SILVER; SILVER IONS; SOLIDS; THIN FILMS