Compton profile study of polycrystalline ytterbium

Abstract

In this paper, we present the first experimental Compton profile of ytterbium. Measurement has been made, at an intermediate resolution (0.40 a.u.), using gamma-ray Compton spectrometry employing a 20 Ci 137 Cs source. In the absence of band-structure calculations, the experimental profile is compared with a free-electron model-based profile and renormalised free-atom (RFA) model. It is seen that the RFA results are comparatively in better agreement with the experiment. Using our Compton profile measurement, we have also derived the cohesive energy of ytterbium.

Compton profile study of thulium

“…Since 6p or 5d electron wave functions or Compton profiles are not available in the literature, it is not possible to consider in detail the contribution of 6p or 5d electron in the valence band of the Tm in its solid state phase. The cohesive energy can be obtained as the difference between bulk and atomic total energies through suggests that the Compton measurements can also predict the cohesive energy of lanthanides as mentioned earlier [9], the limitation being a careful choice of p max in the integral given in Eq. (5).…”

“…along with available data are given in Table 2. As seen in our earlier study on Yb [9], a choice of p max ≥ 2.0 a.u. is justified because after this value the major contribution in the experimental or theoretical profile is due to the core electrons which almost remain unaffected in the formation of solids.…”

Electronic structure of hafnium: A compton profile study

“…Details of experimental set-up have been given elsewhere [19,20]. The above spectrometer has already been used successfully in determining the momentum density of several rare earths and 5d transition metals (see, for example, refs [3][4][5]). The incident γ-rays were allowed to fall normally on the polycrystalline sample (purity 99.9%, dimension 25 × 25 × 1 mm 3 ) and energy spectrum of radiation scattered from the sample was measured with a high-purity Ge detector (Canberra, GLP0210) at a large scattering angle of 160 • ± 0.6 • .…”

“…This model has been applied successfully in our earlier Compton scattering investigation on some rare earth metals and few 5d transition metals (see, for example, refs [3][4][5]). In the present model profiles, we have used the free atom wave functions from the tables of Fischer [27].…”

“…Recently, high-energy γ-ray sources (like 137 Cs) have been used to extend the applicability of Compton profile measurements to materials of high atomic number Z (see, for example, refs [2][3][4][5]). Besides higher resolution (Gaussian FWHM of 0.38 a.u.…”