Articles written in Bulletin of Materials Science

• Novel 1:1 stoichiometric rare-earth HoX (X $=$ Pd, Ag and Cd) intermetallic compounds: DFT-based study

A systematic investigation on structural, electronic, elastic, mechanical and optical properties of novel 1:1 stoichiometric rare-earth HoX (X $=$ Pd, Ag and Cd) intermetallic compounds has been made via ab-initio density functional theory-based linearized augmented plane wave method as coded in wien2k. An outline of local density approximation andgeneralized gradient approximation have been employed. Structural optimization established the stable CsCl-type cubic structure of HoX (X $=$ Pd, Ag and Cd) compounds. The determined crystal structure stability, compressibility and fracture strength of compounds are enhanced with X in the order HoPd > HoAg > HoCd. The interlacing electron dispersion curves at Fermi-level in band structure and density of states substantiate the metallic nature of compounds. The splitting gap between the lower and upper valence bands monotonously becomes narrower with the substitution of heavier core-element(Pd $\to$ Ag $\to$ Cd). The mechanical constants i.e., bulk modulus ($B$), Young’s modulus ($E$), shear modulus ($G_H$), Pugh’s ratio ($B/G_H$), Poisson’s ratio ($v$) and anisotropic factor ($A$) have been calculated to corroborate the mechanical properties of compounds. The cationic nature of Ho-atoms and anionic nature of X-atoms has been evaluated through the effective charge ($Q^∗$) computations. The observed peaks in the low energy region of optical conductivity spectra attribute the intra-band, while the high energy structures are associated with inter-band transitions in HoX (X $=$ Pd, Ag and Cd) compounds. The bond order calculations demonstrate the highest strength of HoCd compound among the herein studied compounds.

• First-principles structural, electronic, optical and bonding properties of scandium-based ternary indide system Sc$_5$T$_2$In$_4$ (T$=$Ni, Pd, Pt)

The structural, electronic and optical properties of rare-earth, scandium-based compounds within the family of RE$_5$-T$_2$-In$_4$ (T$=$Ni, Pd, Pt) intermetallics are calculated by using density functional theory-based orthogonalized linear combination of atomic orbitals method. The studied compounds crystallize in orthorhombic structure with space groupPbam (No. 55). The electronic properties exhibit conducting features of all three compounds. Charge transfer and crystal strength analysis were carried out by computing bond order and effective charge. Regarding optical properties thecomplex dielectric function, optical conductivity and electron energy loss function have been assessed. All the three compounds demonstrate optically anisotropic behaviour for energy values up to 7.0 eV and turned towards isotropicnature at higher energy (>7.0 eV). Optical conductivity spectra designate that the compounds are optically active for visible to UV light. Two major peaks are observed in energy loss spectra, at 13.2 and 32.6 eV, which correspond toplasmonic resonance points. The interatomic bonding characteristics between distinct pair of atoms within each compound have also been elaborated in comprehensive manner.

• # Bulletin of Materials Science

Volume 44, 2021
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Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020