EXAFS study of the temperature dependence of the Debye–Waller factor in ZnSe zincblende compound

Abstract

In this work, we investigate the temperature dependence of the Debye–Waller (DW) factor in a zincblende-type ZnSe crystal. For this purpose, we measured the extended x-ray absorption fine structure spectra at the Zn and Se K edges in the temperature range of 20–573 K. The DW factor can be described by two different models namely Einstein correlated model and Debye correlated model. The parallel and perpendicular DW factors, the Einstein parameters and Debye temperature are determined and discussed. The temperature dependence of the DW factor of the first, second and third bond distances corresponding to each edge are presented and discussed in terms of vibrational motion. The Einstein frequencies are compared to the vibrational densities of states. The vibrational motion of the first and second coordination shells are affected by the vibrational modes below the energy of the transverse optic modes and around the energy of the transverse acoustic modes, respectively. The DW factor extracted for each shell is influenced by different parts of the phonon spectrum.

Combining X-ray Diffraction and X-ray Absorption Spectroscopy to Unveil Zn Local Environment in Zn-Doped ZrO2 Catalysts

“…Reliability of the fit is furthermore confirmed by comparable Einstein temperatures for Zr–Zn (269 ± 24 K) and Zn–Zr (226 ± 26 K) and for Zn–Zn I (174 ± 25 K) and Zn–Zn II (174 ± 26 K) scattering paths (Table S8). The latter also matches literature values . As showed in Table S7, fit reliability is additionally confirmed as values obtained at 312 K/H 2 and 300 K/He from fits carried out with and without the Einstein model, respectively, are entirely comparable.…”

“…The latter also matches literature values. 52 As showed in Table S7, fit reliability is additionally confirmed as values obtained at 312 K/H 2 and 300 K/He from fits carried out with and without the Einstein model, respectively, are entirely comparable. Noteworthy, the same Zn K-edge second-shell dynamic was observed in the FT-EXAFS of ZrZn-30 catalyst reported in Figure S19.…”

Optimization of magnetic properties of BaTiO3/Li0.5Fe2.5O4 multiferroics prepared via modified low-temperature combustion

“…The Italian 11.1 XAFS beamline of Elettra synchrotron radiation source in Trieste-Italy was used for XAFS data collection around 7112 keV of Fe Kedge [21]. The sample was finely powdered and composited into polyvinyl pyrrolidine (PVP) matrix and then pressed into pellet with a diameter of 13 mm and with a proper highly uniform optical thickness.…”