The phonon frequency distribution of vanadium

Measurements of neutrons scattered inelastically from vanadium have been made and absolute cross sections determined over a range of energy and momentum transfers of 0-50 meV and 1-12 Å -1 respectively. A frequency distribution of the normal modes of vibration in vanadium is evaluated from these data Peaks are observed at energy transfers of 8, 20 5, 25 5 and 28 5 meV (equal to 1 9, 4 9, 6 1 and 6 9 × 10 -12 sec -1 ). Neutron spectra have been calculated using this distribution and good agreement obtained with experimental data. A comparison is made with the frequency distributions of niobium and tantalum.