skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Structural transition in sputter-deposited amorphous germanium films by aging at ambient temperature

Abstract

The structure of amorphous Ge (a-Ge) films prepared by sputter-deposition and the effects of aging at ambient temperature and pressure were studied by pair-distribution-function (PDF) analysis from electron scattering and molecular dynamics simulations. The PDFs of the as-deposited and aged samples for 3–13 months showed that the major peaks for Ge-Ge bonds decrease in intensity and broaden with aging for up to 7 months. In the PDFs of a-Ge of molecular dynamics simulation obtained by quenching liquid at different rates, the major peak intensities of a slowly cooled model are higher than those of a rapidly cooled model. Analyses on short- and medium-range configurations show that the slowly cooled model includes a certain amount of medium-range ordered (MRO) clusters, while the rapidly cooled model includes liquid-like configurations rather than MRO clusters. The similarity between experimental and computational PDFs implies that as-deposited films are similar in structure to the slowly cooled model, whereas the fully aged films are similar to the rapidly cooled model. It is assumed that as they undergo room-temperature aging, the MRO clusters disintegrate and transform into liquid-like regions in the same matrix. This transition in local configurations is discussed in terms of instability and the non-equilibrium ofmore » nanoclusters produced by a vapor-deposition process.« less

Authors:
;  [1]; ;  [2];  [3]
  1. Department of Materials Science, Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Naka-ku, Sakai 599-8531 (Japan)
  2. Department of Materials Science and Engineering, Kyushu Institute of Technology, Tobata, Kitakyushu, Fukuoka 804-8550 (Japan)
  3. Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Mihogaoka 7-1, Ibaraki, Osaka 567-0047 (Japan)
Publication Date:
OSTI Identifier:
22596757
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 119; Journal Issue: 21; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AGING; AMBIENT TEMPERATURE; AMORPHOUS STATE; COMPUTERIZED SIMULATION; CONFIGURATION; DEPOSITION; DEPOSITS; DISTRIBUTION FUNCTIONS; ELECTRONS; FILMS; GERMANIUM; LIQUIDS; MOLECULAR DYNAMICS METHOD; NANOSTRUCTURES; PEAKS; QUENCHING; SPUTTERING; TEMPERATURE RANGE 0273-0400 K; VAPOR DEPOSITED COATINGS

Citation Formats

Okugawa, M., Nakamura, R., E-mail: nakamura@mtr.osakafu-u.ac.jp, Numakura, H., Ishimaru, M., Watanabe, K., and Yasuda, H. Structural transition in sputter-deposited amorphous germanium films by aging at ambient temperature. United States: N. p., 2016. Web. doi:10.1063/1.4953234.
Okugawa, M., Nakamura, R., E-mail: nakamura@mtr.osakafu-u.ac.jp, Numakura, H., Ishimaru, M., Watanabe, K., & Yasuda, H. Structural transition in sputter-deposited amorphous germanium films by aging at ambient temperature. United States. doi:10.1063/1.4953234.
Okugawa, M., Nakamura, R., E-mail: nakamura@mtr.osakafu-u.ac.jp, Numakura, H., Ishimaru, M., Watanabe, K., and Yasuda, H. Tue . "Structural transition in sputter-deposited amorphous germanium films by aging at ambient temperature". United States. doi:10.1063/1.4953234.
@article{osti_22596757,
title = {Structural transition in sputter-deposited amorphous germanium films by aging at ambient temperature},
author = {Okugawa, M. and Nakamura, R., E-mail: nakamura@mtr.osakafu-u.ac.jp and Numakura, H. and Ishimaru, M. and Watanabe, K. and Yasuda, H.},
abstractNote = {The structure of amorphous Ge (a-Ge) films prepared by sputter-deposition and the effects of aging at ambient temperature and pressure were studied by pair-distribution-function (PDF) analysis from electron scattering and molecular dynamics simulations. The PDFs of the as-deposited and aged samples for 3–13 months showed that the major peaks for Ge-Ge bonds decrease in intensity and broaden with aging for up to 7 months. In the PDFs of a-Ge of molecular dynamics simulation obtained by quenching liquid at different rates, the major peak intensities of a slowly cooled model are higher than those of a rapidly cooled model. Analyses on short- and medium-range configurations show that the slowly cooled model includes a certain amount of medium-range ordered (MRO) clusters, while the rapidly cooled model includes liquid-like configurations rather than MRO clusters. The similarity between experimental and computational PDFs implies that as-deposited films are similar in structure to the slowly cooled model, whereas the fully aged films are similar to the rapidly cooled model. It is assumed that as they undergo room-temperature aging, the MRO clusters disintegrate and transform into liquid-like regions in the same matrix. This transition in local configurations is discussed in terms of instability and the non-equilibrium of nanoclusters produced by a vapor-deposition process.},
doi = {10.1063/1.4953234},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 21,
volume = 119,
place = {United States},
year = {2016},
month = {6}
}