Compton profile study of thulium

Abstract

PACS 71.15.Nc, 78.70.Ck First high-precision measurement of the isotropic Compton spectra of thulium has been carried out, at an intermediate resolution of 0.40 a.u., using 137 Cs as a γ-ray source. For the interpretation of data, theoretical calculations were undertaken using renormalised-free-atom (RFA) and free electron models. It is seen that the RFA calculation with e --e -correlation gives a better agreement with the experiment. From our experimental and theoretical Compton profile data, we have also computed for the first time the cohesive energy of thulium and compared it with available data.

Electronic structure of hafnium: A compton profile study

“…For the calculation of cohesive energy from the experimental data, the problem related to p 2 weighting in high momentum has been highlighted earlier (see, for example, refs [3][4][5]). To avoid such problems in the present computation of cohesive energy from the experimental data, we have taken p max = 2.0 a.u.…”

“…Very recently, the use of Compton profiles to infer cohesive energy of several rare earths has aroused considerable interest [3][4][5]. The cohesive energy can be calculated using the relation…”

“…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.…”