• B K Sharma

Articles written in Pramana – Journal of Physics

• Shape change in Hf, W and Os-isotopes: A non-relativistic Hartree-Fock versus relativistic Hartree approximation

We have investigated the ground-state structures of even-even Hf, W and Os isotopes within the framework of a deformed non-relativistic Hartree-Fock and a relativistic mean field formalism. A majority of the nuclei are predicted to be prolate in shape in the relativistic calculations. On the other hand, contrary to the relativistic results, we predict a shape change in a cyclic order in the non-relativistic calculations. However, in both the cases, the magnitude of the quadrupole deformation parameter agrees well with the experimental data. We also evaluated the hexadecapole deformation parameter for Hf, W and Os isotopes and irrespective of the shape change in quadrupole moments, we find a cyclic change in hexadecapole shape from positive to negative and vice versa in both the relativistic and non-relativistic formalisms.

• A variable electron beam and its irradiation effect on optical and electrical properties of CdS thin ﬁlms

A low energy electron accelerator has been constructed and tested. The electron beam can operate in low energy mode (100 eV to 10 keV) having a beam diameter of 8–10 mm. Thin ﬁlms of CdS having thickness of 100 nm deposited on ITO-coated glass substrate by thermal evaporation method have been irradiated by electron beam in the above instrument. The $I–V$ characteristic is found to be nonlinear before electron irradiation and linear after electron irradiation. The TEP measurement conﬁrms the n-type nature of the material. The TEP and $I–V$ measurements also conﬁrm the modiﬁcation of ITO/CdS interface with electron irradiation.

• Compton profile study of V3Ge and Cr3Ge

In this paper the results of a Compton profile study of two polycrystalline A15 compounds, namely, V3Ge and Cr3Ge, have been reported. The measurements have been performed using 59.54 keV 𝛾-rays from an 241Am source. The theoretical Compton profiles have been computed for both the compounds using ab-initio linear combination of atomic orbitals (LCAO) method employing CRYSTAL98. For both the A15 compounds, the isotropic experimental profiles are found to be in good overall agreement with the calculations. The comparison points out residual differences in V3Ge whereas for Cr3Ge the differences are within experimental error. The behaviour of valence electrons in the two iso-structural compounds has been examined on the scale of Fermi momentum. The valence electron distribution seems to be dominated by the metallic constituents rather than Ge and two compounds show covalent nature of bonding which is larger in V3Ge compared to Cr3Ge.

• # Pramana – Journal of Physics

Volume 94, 2020
All articles
Continuous Article Publishing mode

• # Editorial Note on Continuous Article Publication

Posted on July 25, 2019