MEASUREMENT OF DEBYE-WALLER-FACTOR FOR ELECTRON DIFFRACTION AT ALKALIHALIDES

The influence of thermal vibrations on the electron diffraction intensities (50 keV) of polycrystalline alkalihalide foils (LiF, LiCl, NaF and NaCl) has been studied. The ring intensities were measured at foil temperatures 150 and 475 °K by means of a retarding field apparatus. From the intensities of all reflections, which behave kinematically, the Debye-Waller factor exp(-M) and the mean square displacement 〈u2〉 for the different metal and halogen ions have been determined. The measured 〈u2〉-values agree fairly well with theoretical values and with experimental results obtained from X-ray and neutron diffraction measurements. © 1968 Springer-Verlag.