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Title: Comparative studies of positron annihilation lifetime and coincident Doppler broadening spectra for a binary Cd-based quasicrystal and 1/1-approximant crystal

Abstract

We performed the positron annihilation lifetime and coincident Doppler broadening measurements for binary icosahedral quasicrystal Cd{sub 5.7}Ca and its 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants. Since the obtained positron lifetimes are quite similar to one another, it is likely that the same type of structural vacancies exists in quasicrystal Cd{sub 5.7}Ca and 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants. The vacancy-type defects are concluded to be surrounded mostly by Cd atoms in both quasicrystal Cd{sub 5.7}Ca and its 1/1-cubic approximant Cd{sub 6}Ca from the high-momentum Doppler broadening spectra. In addition, we studied the temperature dependence of the positron annihilation lifetime in the low temperature region from 10 to 300 K for 1/1-cubic approximant Cd{sub 6}Ca and Cd{sub 6}Yb crystals. As a whole, in both 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants the positron lifetime {tau}{sub 1} gradually increases with increasing temperature due to isotropic thermal expansion. However, the positron lifetime {tau}{sub 1} does not change at the order-disorder transition temperature, namely, 100 and 110 K for 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants, respectively. These results suggest that the size of the structural vacancies and local electron density do not change with the ordering.

Authors:
; ; ; ; ; ;  [1]
  1. Department of Physics, Tokyo Gakugei University, 4-1-1 Koganei, Tokyo 184-0051 (Japan)
Publication Date:
OSTI Identifier:
20787943
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 73; Journal Issue: 9; Other Information: DOI: 10.1103/PhysRevB.73.092202; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1098-0121
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; ANNIHILATION; CADMIUM ALLOYS; CALCIUM ALLOYS; CRYSTALS; DOPPLER BROADENING; ELECTRON DENSITY; LIFETIME; ORDER-DISORDER TRANSFORMATIONS; POSITRONS; TEMPERATURE DEPENDENCE; THERMAL EXPANSION; VACANCIES; YTTERBIUM ALLOYS

Citation Formats

Takagiwa, Y, Kanazawa, I, Sato, K, Murakami, H, Kobayashi, Y, Tamura, R, Takeuchi, S, Department of Environmental Science, Tokyo Gakugei University, 4-1-1 Koganei, Tokyo 184-0051, National Institute of Advanced Industrial Science and Technology, and Department of Materials Science and Technology, Tokyo University of Science, Noda, Chiba 278-8501. Comparative studies of positron annihilation lifetime and coincident Doppler broadening spectra for a binary Cd-based quasicrystal and 1/1-approximant crystal. United States: N. p., 2006. Web. doi:10.1103/PHYSREVB.73.0.
Takagiwa, Y, Kanazawa, I, Sato, K, Murakami, H, Kobayashi, Y, Tamura, R, Takeuchi, S, Department of Environmental Science, Tokyo Gakugei University, 4-1-1 Koganei, Tokyo 184-0051, National Institute of Advanced Industrial Science and Technology, & Department of Materials Science and Technology, Tokyo University of Science, Noda, Chiba 278-8501. Comparative studies of positron annihilation lifetime and coincident Doppler broadening spectra for a binary Cd-based quasicrystal and 1/1-approximant crystal. United States. https://doi.org/10.1103/PHYSREVB.73.0
Takagiwa, Y, Kanazawa, I, Sato, K, Murakami, H, Kobayashi, Y, Tamura, R, Takeuchi, S, Department of Environmental Science, Tokyo Gakugei University, 4-1-1 Koganei, Tokyo 184-0051, National Institute of Advanced Industrial Science and Technology, and Department of Materials Science and Technology, Tokyo University of Science, Noda, Chiba 278-8501. Wed . "Comparative studies of positron annihilation lifetime and coincident Doppler broadening spectra for a binary Cd-based quasicrystal and 1/1-approximant crystal". United States. https://doi.org/10.1103/PHYSREVB.73.0.
@article{osti_20787943,
title = {Comparative studies of positron annihilation lifetime and coincident Doppler broadening spectra for a binary Cd-based quasicrystal and 1/1-approximant crystal},
author = {Takagiwa, Y and Kanazawa, I and Sato, K and Murakami, H and Kobayashi, Y and Tamura, R and Takeuchi, S and Department of Environmental Science, Tokyo Gakugei University, 4-1-1 Koganei, Tokyo 184-0051 and National Institute of Advanced Industrial Science and Technology and Department of Materials Science and Technology, Tokyo University of Science, Noda, Chiba 278-8501},
abstractNote = {We performed the positron annihilation lifetime and coincident Doppler broadening measurements for binary icosahedral quasicrystal Cd{sub 5.7}Ca and its 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants. Since the obtained positron lifetimes are quite similar to one another, it is likely that the same type of structural vacancies exists in quasicrystal Cd{sub 5.7}Ca and 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants. The vacancy-type defects are concluded to be surrounded mostly by Cd atoms in both quasicrystal Cd{sub 5.7}Ca and its 1/1-cubic approximant Cd{sub 6}Ca from the high-momentum Doppler broadening spectra. In addition, we studied the temperature dependence of the positron annihilation lifetime in the low temperature region from 10 to 300 K for 1/1-cubic approximant Cd{sub 6}Ca and Cd{sub 6}Yb crystals. As a whole, in both 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants the positron lifetime {tau}{sub 1} gradually increases with increasing temperature due to isotropic thermal expansion. However, the positron lifetime {tau}{sub 1} does not change at the order-disorder transition temperature, namely, 100 and 110 K for 1/1-cubic Cd{sub 6}Ca and Cd{sub 6}Yb approximants, respectively. These results suggest that the size of the structural vacancies and local electron density do not change with the ordering.},
doi = {10.1103/PHYSREVB.73.0},
url = {https://www.osti.gov/biblio/20787943}, journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 9,
volume = 73,
place = {United States},
year = {2006},
month = {3}
}