First-shell low-temperature study of zincblende-type ZnS by the EXAFS technique using the cumulant method

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 to 300 K in order to investigate the local structure and temperature effect in a zincblende-type ZnS compound. The cumulant method is used for this purpose. The temperature dependence of the bond distance and the Debye-Waller factor is determined and discussed in terms of anisotropy. It is shown that these characteristic parameters increase with increasing temperature, demonstrating the nonnegligible thermal (NTE) effect due to the increase of the relative vibration in parallel and perpendicular directions with respect to the bond direction. Agreement is found with other zincblende structure compounds studied by the EXAFS technique. 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.