Pressure Dependence of Anharmonic Effective Pair Potentials in Rock Salt Type AgI

Journal Article · Fri Feb 02 04:00:00 EST 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2644596· OSTI ID:21054684

Yoshiasa, Akira; Sugahara, Masahiko ^[1]; Fukui, Hiroshi; Arima, Hiroshi; Ohtaka, Osamu ^[2]; Okube, Maki ^[3]; Katayama, Yoshinori ^[4]; Murai, Kei-ichiro ^[5]

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1. Graduate School of Science, Kumamoto University, Kumamoto 860-8555 (Japan)
2. Graduate School of Science, Osaka University, Toyonaka 560-0043 (Japan)
3. Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-850 (Japan)
4. Spring-8, Japan Atomic Energy Research Institute, Hyogo 679-5198 (Japan)
5. Faculty of Engineering, Tokushima University, Tokushima 770-8506 (Japan)

Pressure dependence of anharmonic effective pair potentials V(u)=au2/2+bu3/3{exclamation_point} for the I-Ag bond in rock salt type AgI has been investigated by EXAFS Debye-Waller factors. EXAFS measurements near the I K-edge were performed under pressure up to 6.0 GPa using a multi-anvil high-pressure device and synchrotron radiation from SPring-8, Hyogo. The potential parameter a for rock-salt type is 1.66(5) eV/A2 at 1.0 GPa and increases to 1.88(6) eV/A2 at 6.0 GPa. The phonon energies in rock salt type AgI under pressure have been estimated using the potential parameter a by calculating the dynamical matrix. The anharmonic effective pair potential for each phase is influenced by pressure and becomes steeper with increasing pressure while the extent of anharmonicity decreases with pressure.

• OSTI ID: 21054684
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 882; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
CHEMICAL BONDS
DEBYE-WALLER FACTOR
EV RANGE
FINE STRUCTURE
PHONONS
POTENTIALS
PRESSURE DEPENDENCE
PRESSURE RANGE GIGA PA
SILVER IODIDES
SPRING-8 STORAGE RING
SYNCHROTRON RADIATION
X-RAY SPECTROSCOPY