학술논문
Extended X-ray Absorption Fine Structure (EXAFS) Measurements on Alkali Metal Superatoms of Ta-Atom-Encapsulated Si 16 Cage.
Document Type
Academic Journal
Author
Inoue T; Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.; Ina T; Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo 679-5198, Japan.; Masai H; National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan.; Kondo N; Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan.; Matsui F; Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan.; SOKENDAI (The Graduate University for Advanced Studies), Myodaiji, Okazaki 444-8585, Japan.; Kinoshita T; Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo 679-5198, Japan.; Nakajima A; Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
Source
Publisher: American Chemical Society Country of Publication: United States NLM ID: 101526034 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1948-7185 (Electronic) Linking ISSN: 19487185 NLM ISO Abbreviation: J Phys Chem Lett Subsets: PubMed not MEDLINE; MEDLINE
Subject
Language
English
Abstract
The silicon cage nanoclusters encapsulating a tantalum atom, termed Ta@Si 16 , exhibit characteristics of alkali metal "superatoms (SAs)". Despite this conceptual framework, the precise structures of Ta@Si 16 and Ta@Si 16 + remain unclear in quantum calculations due to three energetically close structural isomers: C 3v , T d , and D 4d structures. To identify the geometrical structure of Ta@Si 16 SAs, structural analysis was conducted using extended X-ray absorption fine structure (EXAFS) with a high-intensity monochromatic X-ray source, keeping anaerobic conditions. Focusing on "superordered" films, which constitute amorphous thin films composed solely of Ta@Si 16 SAs, this analysis preserved locally ordered structures. Spectral comparisons between experimental and simulated Ta L 3 -edge EXAFS unveil that Ta@Si 16 SAs on a substrate adopt a C 3v -derived structure, while Si K -edge EXAFS introduces spectral ambiguity in structural identifications, attributed to both intracluster and intercluster scatterings. These findings underscore the significance of locally ordered structure analyses in understanding and characterizing novel nanoscale materials.