Pressure dependence of effective pair potentials in AgBr determined by extended X-ray absorption fine structure

Yoshiasa, Akira*; Murai, Keiichiro*; Nagai, Takaya*; Katayama, Yoshinori

The pressure dependence of extended X-ray absorption fine structure (EXAFS) Debye-Waller factors in AgBr has been investigated using the cumulant expansion method. The Br K-edge EXAFS spectra were measured in the transmission mode under high pressure (9.1GPa) at room temperature using a cubic anvil type apparatus (MAX90) and synchrotron radiation from the Photon Factory, Tsukuba. The effective pair potentials , were evaluated and the potential coefficient at 2.1, 4.2 and 6.1GPa are 1.59(4), 1.75(4) and 1.91(4) eV/, respectively. The energies of the third-order anharmonic potential coefficient maintain nearly constant values with pressure though the third-order cumulant decreases with increasing in pressure.