Mechanical, electronic and optical properties of Bi2S3 and Bi2Se3 compounds: first principle investigations

Cataloged from PDF version of article.The structural, mechanical, electronic, and optical properties of orthorhombic Bi2S3 and Bi2Se3 compounds have been investigated by means of first principles calculations. The calculated lattice parameters and internal coordinates are in very good agreement with the experimental findings. The elastic constants are obtained, then the secondary results such as bulk modulus, shear modulus, Young's modulus, Poisson's ratio, anisotropy factor, and Debye temperature of polycrystalline aggregates are derived, and the relevant mechanical properties are also discussed. Furthermore, the band structures and optical properties such as real and imaginary parts of dielectric functions, energy-loss function, the effective number of valance electrons, and the effective optical dielectric constant have been computed. We also calculated some non-linearities for Bi2S3 and Bi2Se3 (tensors of elasto-optical coefficients) under pressur

Optical and magnetic properties of some XMnSb and Co2YZ Compounds: ab initio calculations

In present work, our research is mainly focused on the electronic structures, optical, and magnetic properties of XMnSb (X = Ni, Cu, Pd), Co2YZ (Y = Ti; Z=Si, Ge, Sn), and Co2YZ (Y =Mn; Z=Al, Ga, Si) Heusler compounds by using ab initio calculations within the generalized gradient approximation. The calculations are performed by using the Vienna ab initio simulation package based on the density functional theory. The band structure of these Heusler alloys for majority spin and minority spin were calculated and the majority spin states cross the Fermi level and thus have the metallic character, while the minority spin states open the band gaps around the Fermi level and thus have the narrow-band semiconducting nature. We also find that these Heusler compounds have the indirect band gaps in the minority spin channel. The real and imaginary parts of dielectric functions and hence the optical functions such as energy-loss function, the effective number of valance electrons and the effective optical dielectric constant for XMnSb and Co2YZ compounds were also calculated. In addition, we also show the variations of the total magnetic moment per f.u. and minority spin gap width of these compounds with optimized lattice constants: minority spin gap width decreases with increasing the lattice constants. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Optical and electronic properties of orthorhombic and trigonal AXO3 (A=Cd, Zn; X=Sn, Ge): First principle calculation

Electronic structure and optical properties of the CdXO3 and ZnXO3 (X˭Ge, Sn) compounds have been investigated based on density functional theory. According to the predictive results, reveal that the CdXO3 and ZnXO3 would be candidates for a high performance lead free optical crystal, which will avoid the environmental toxicity problem of the lead-based materials. © 2016, © Taylor & Francis Group, LLC

Electronic structure of fluorides: general trends for ground and excited state properties

The electronic structure of fluorite crystals are studied by means of density functional theory within the local density approximation for the exchange correlation energy. The ground-state electronic properties, which have been calculated for the cubic structures $CaF_{2}$,$SrF_{2}$, $BaF_{2}$, $CdF_{2}$, $HgF_{2}$, $\beta$-$PbF_{2}$, using a plane waves expansion of the wave functions, show good comparison with existing experimental data and previous theoretical results. The electronic density of states at the gap region for all the compounds and their energy-band structure have been calculated and compared with the existing data in the literature. General trends for the ground-state parameters, the electronic energy-bands and transition energies for all the fluorides considered are given and discussed in details. Moreover, for the first time results for $HgF_{2}$ have been presented

A kinetic study of mercury(II) transport through a membrane assisted by new transport reagent

Background: A new organodithiophosphorus derivative, namely O-(1,3-Bispiperidino-2-propyl)-4-methoxy phenyldithiophosphonate, was synthesized and then the kinetic behavior of the transport process as a function of concentration, temperature, stirring rate and solvents was investigated.Results: The compound 1 was characterized by elemental analysis, IR, H-1 and P-31 NMR spectroscopies. The transport of mercury(II) ion by a zwitterionic dithiophosphonate 1 in the liquid membrane was studied and the kinetic behavior of the transport process as a function of concentration, temperature, stirring rate and solvents was investigated. The compound 1 is expected to serve as a model liquid membrane transport with mercury(II) ions.Conclusion: A kinetic study of mercury(II) transport through a membrane assisted by O-(1,3-Bispiperidino-2-propyl)4-methoxy phenyldithiophosphonate was performed. It can be concluded that the compound 1 can be provided a general and straightforward route to remove toxic metals ions such as mercury(II) ion from water or other solution

derivatives and selective extraction of Fe3+

Five new polymeric compounds containing more than one calix[4]arene have been synthesized by reacting an oligomer with 5,11,17,23-tetrakis[(diethylamino)methyl]-25,26,27,28-tetrahydroxycalix[4]arene (M), 25, 27-dimethyl-26,28-dihydroxy-p-tert-butylcalix[4]arene diketone (1,2), and p-nitrocalix[4]arene (1,3), and chloro-methylated polystyrene with 25,27-dimethyl-26,28-dihydroxy-p-tert-butylcalix[4]arene diketone (L4) and p-nitrocalix[4]arene (1,5). These compounds were studied by the selective extraction of Fe3+ cation from the aqueous phase into the organic phase and was carried out by using compounds L1-L5. It was observed that the polymer support attached to the lower rim of p-nitrocalix[4]arene was the most efficient carrier of Fe3+ in the extraction process

derivatives

Two compounds (1 and 2) which have calix[4]arene units and their Na+ and K+-complexes were prepared. All the complexes have a metal-ligand ratio of 1 : 1. The newly prepared compounds were characterized on the basis of their H-1 NMR, IR, UV-visible as well as elemental analysis

derivatives

In this study, seven new compounds p-(4-butyl-phenylazo) calix[6] arene (1), p-(4-(phenylazo) phenylazo) calix[ 6] arene (2), p-(4-hydroxyphenylazo) calix[6] arene (3), p-{4-[N-(thiazol-2-yl) sulfamoyl] phenylazo} calix[6] arene (4), p-(4-acetamidophenylazo) calix[6] arene (5), p-(thiazol-2-ylazo) calix[6] arene (6) and p-(2-sulfanylphenylazo) calix[6] arene (7) have been synthesized from calix[6] arene by diazo coupling with the corresponding aromatic amines. UV- Vis, IR, H-1 and C-13 NMR spectral data have been used to elucidate the structures of the compounds elemental analyses

calix[n]arene derivatives

Two different azo derivatives of p-tert butylcalix[4 and 6]arene 5a, 5b have been synthesised; treatment of the monomers (phenol and p-tert-butyl phenol) with diazonium chloride (3) provided corresponding compounds 4a, 4b