Debye-Waller factor and thermal expansion of arsenic, antimony and bismuth

The Debye-Waller factors of polycrystalline As, Sb and Bi, obtained by neutron diffraction in the temperature range of 5K up to almost the melting point, are compared with lattice dynamics model calculations and results from X-ray and Mossbauer effect measurements. Within experimental accuracy the thermal motions appear to be isotropic and almost harmonic except for Bi at high temperatures. Moreover, the temperature dependence of the lattice constants and the positional parameter z were determined.