Characterization of alpha and beta phases of tantalum coatings

Sputtered tantalum forms two phases - α and β. The α and β phases have distinctly different crystalline structures and properties. The structure and the causes of formation of the β phase are still being studied by researchers. This is a study to distinguish and characterize these two phases. Samples from Bennet Labs and NJIT were characterized using techniques such as SEM, EDX, XRF, XRD, TEM and XAFS. Samples deposited at NJIT were used for an experimental study on the conditions favoring the formation of the phases, by depositing tantalum on heated steel and silicon substrates, additionally TEM analysis was carried out for a sample having a mixture of α and β phases to study its differences. The XRD results shows one of the sample to be highly textured β Tantalum. The XAFS results also show the α. phase to have a bcc structure with the characterstic coordination of bulk tantalurn.The local structure of β tantalum is compared to a theoretical model of P41mnm space group. The study confirm that the structure of tantalum belongs to this space group and has a 30-atom unit cell isomorphous with Uranium. The coordination of Ta atoms in the β phase is seen to be non isotropic. The results of the heating experiments suggest that coatings deposited on substrates without heating favored the formation of the β phase. The TEM analysis shows the β phase to be made up of larger grains of size 100-120 nm, which are about 4 times the size of the αphase grains

Investigation of the structure of beta-Tantalum

The local structure of beta-tantalum was investigated by comparing experimental extended x-ray absorption fine structure (EXAFS) measurements with calculated spectra of proposed models. Four possible structure candidates were examined: a beta-Uranium based structure, a distorted A15 structure, a bcc-Ta based superlattice structure with N interstitials and a simple hcp structure. The local structural measurements were found to be consistent with the beta-Uranium based model containing 30 atoms per unit cell and having the space group P42/mnm. The thermal effect analysis on x-ray diffraction and EXAFS spectra, which reveals that beta-Ta is highly disordered, agrees with the low symmetry and anisotropic system of the beta-U model.Comment: 26 pages, two tables, 8 figures, submitted to Journal of Applied physic

Molecular structure, chemical reactivity and molecular docking studies of 1,7,8,9-tetrachloro-10,10-dimethoxy-4-[3-(4-benzylpiperazine-1-yl)propyl]-4-azatricyclo[5.2.1.02,6] dec-8-ene-3, 5-dione

1,7,8,9-tetrachloro-10,10-dimethoxy-4-[3-(4-benzylpiperazine-1-yl)propyl]-4-azatricyclo[5.2.1.02,6] dec-8-ene-3, 5-dione (TCDBPAD) have been calculated theoretically to obtain optimized geometry, vibrational frequencies and corresponding vibrational assignments. Charge transfer within the molecule was evaluated using HOMO and LUMO analysis. By hyper-conjugative interaction and charge delocalisation which can be analysed using NBO analysis, we can understand about the stability of the molecule. By using DFT method Molecular electrostatic potential (MEP) was calculated. First hyperpolarizability values are calculated in order to check the non-linear optical activity. Using MD simulations, we have visualized the ALIE and Fukui functions. The degradation property of compound in presence of water was evaluated using RDF curves. By solubility parameter we have identified suitable excipient for the title compound. Molecular docking studies proved that the title compound can be used for the treatment of Cardiovascular and Cerebrovascular diseases

Spectroscopic investigations, DFT calculations, molecular docking and MD simulations of 3-[(4-Carboxyphenyl) carbamoyl]-4-hydroxy-2-oxo-1, 2-dihydroxy quinoline-6-carboxylic acid.

By FT-IR, FT-Raman and DFT computations spectral characterization of 3-[(4-Carboxyphenyl) carbamoyl]-4-hydroxy-2-oxo-1, 2-dihydroxy quinoline-6-carboxylic acid was performed. Computational calculations were done using B3LYP/6-31G(d’) basis set. Vibrational assignments of wavenumbers were performed on the basis of potential energy distribution. Donor acceptor interactions were evaluated using NBO analysis. To foresee the important reactive sites of the title compound we combined DFT calculations and molecular dynamics (MD) and visualized the ALIE and Fukui functions. Sensitive nature of the compound towards autoxidation and degradation in the presence of water was investigated by the calculation of BDE and RDF. By molecular docking the compound forms a stable complex with ubiquinol-cytochrome–c reductase inhibitor

Spectroscopic characterization, docking studies and reactive properties by DFT calculations of halogen substituted 6-Chloro-N-(3-iodo-4-methylphenyl)-pyrazine-2-carboxamide with MD simulations.

The spectral characterization of 6-Chloro-N-(3-iodo-4-methylphenyl)-pyrazine-2-carboxamide (CIMPPC) was executed by FT-IR and FT-Raman spectroscopic methods and density functional theory (DFT) computations have been carried using B3LYP/gen method. On the basis of potential energy distribution (PED) the vibrational assignments of the wavenumbers were proposed. NBO analysis was performed to study donor acceptor interactions. Halogen substitution results in increase in the µ (chemical potential) value in comparison with the parent molecule, which is a minimum. Halogen substitution also results a decrease in electrophilicity index. Fundamental reactive properties of the title molecule is investigated by MEP analysis. Visualization of ALIE and Fukui functions evaluated the most probable sites for electrophilic attacks. Exposure of the title compound towards autoxidation and hydrolysis is evaluated using BDE and RDF. The compatible nature of the compound is investigated through the Hildebrand solubility parameter. CIMPPC exhibit inhibitory activity against the anti-inflammatory receptor transient receptor potential cation channel