Pressure effects on the EXAFS Debye-Waller factor of iron.
J Synchrotron Radiat
; 27(Pt 5): 1372-1375, 2020 Sep 01.
Article
em En
| MEDLINE
| ID: mdl-32876614
ABSTRACT
The pressure effects on atomic mean-square relative displacement characterizing the extended X-ray absorption fine structure (EXAFS) Debye-Waller factor of iron metal have been investigated based on the Debye model. The analytical expressions of the Debye frequency and EXAFS Debye-Waller factor have been derived as functions of crystal volume compressibility. Based on the well established equation-of-state including the contributions of the anharmonic and electronic thermal pressures, numerical calculations have been performed for iron up to a pressure of 220â
GPa and compared with experimental data when possible. These results show that the Debye frequency increases rapidly with compression, and beyond 150â
GPa it behaves as a linear function of pressure. Meanwhile the mean-square relative displacement curve drops robustly with pressure, especially at pressures smaller than 100â
GPa. This phenomenon causes the enhancement of EXAFS signals at high pressure. Reversely, the increasing of temperature will reduce the amplitude of EXAFS spectra.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Synchrotron Radiat
Assunto da revista:
RADIOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Vietnã