Low-range thermal investigation of zincblende-type ZnS by combined extended X-ray absorption fine structure and X-ray diffraction techniques

Abstract Extended X-ray absorption fine structure (EXAFS) has been measured at the zinc K edge in zinc sulfide (ZnS), in the temperature range of 20 K–300 K, in order to investigate the local structure and temperature effect in a zincblende-type ZnS compound. X-ray Diffraction (XRD) data have been carried out at the temperature range of 100 K–300 K for the investigation of the crystallographic local structure of ZnS. The cumulant method and the least-square fitting procedures are used in the EXAFS technique whereas the Rietveld method is used for the refinement of the XRD experimental data. The temperature dependence and the thermal expansion of the first bond distance and the Debye-Waller factor are exhibited and discussed in terms of anisotropy. The difference between the first bond distance measured by EXAFS and XRD is discussed. The Einstein frequencies are compared to the vibrational densities of states (VDOS) due to: the transverse acoustic mode, longitudinal acoustic and/or optic phonon modes; while the force constants have been correlated with the valence force field (VFF) models.