Temperature factors of polycrystalline arsenic, antimony and bismuth in the low-temperature range

The Debye-Waller factors B of polycrystalline As, Sb and Bi are measured by neutron diffraction in the temperature range 5-293K. At the lowest temperatures presumably quantum effects of zero-point motion are dominant in the temperature factors of As, whereas at higher temperatures there is a linear increase of B with temperature as expected from Debye theory. Within experimental accuracy the thermal motions appear to be isotropic.