Computational Analysis and First Principle Study of Electrical and Optical Properties of Fe Doped SWBNNT and its Application

The electrical and optical properties of One Dimension-Single Walled Boron Nitride Nanotube (1D-SWBNNT) doped with transition metal Iron are studied using the Quantum ATK. Highest direct bandgap obtained for S1 as 5.3167eV and S3 as 3.5328eV depicted the possibility of its use as a dielectric in the memory device. SWBNNT showed a consistent bandgap for varying lengths of the NT. Bandgap tunability and a moderate increase in the number of states in Density of States (DOS) plots can be achieved by the inclusion of transition metal dopants in pristine SWBNNT. In Projected-DOS (PDOS) plots we observed N and Fe atoms as the majority contributor of electronic states in the valence band and Fe atom as the main contributor in the conduction band. The inclusion of Fe dopant leads to an increase in the wavelength and optical gap. High optical conductivity for S2, S3, and S4 depicts its use as composites in photoconductive devices. The incorporation of Fe dopant led to a rise in susceptibility (χ) where S1 and S2-S4 showed a weak diamagnetic and strong paramagnetic property. BNNTs technologies are still growing, there is a need for further development bringing out its vast applications in the future.

Synthesis, Characterization and Antibacterial Properties of Nickel(II) Complex with 4-Aminoantipyrine Ligand

The novel nickel(II) complex has been successfully synthesized through the reaction of Ni(NO3)2·6H2O with 4-aminoantipyrine (AAP) ligand in a 1:3 mole ratio of Ni(II) to AAP. The complex was characterized using UV-Vis, Atomic Absorption Spectroscopy (AAS), Infrared spectrophotometry (IR), Thermogravimetry/Differential Scanning Calorimetry (TG/DSC), conductivity, and magnetic susceptibility. The complex formula was [Ni(AAP)3](NO3)2·5H2O. AAP was a bidentate ligand that coordinated through the primary amine nitrogen and the carbonyl oxygen to the nickel ion. The electronic spectra of the complex displayed two peaks at 646 nm and 385 nm in accordance with the 3A2g(F) → 3T1g(F) and 3A2g(F) → 3T1g(P) transitions, respectively. This complex gave a paramagnetic property with the effective magnetic moment (µeff) of 2.96 BM and the shape of an octahedron. The antibacterial test of this complex showed higher activity than the metal and its free ligand.

Detail investigation of thermoelectric performance and magnetic properties of Cs-doped Bi2Sr2Co2Oy ceramic materials

Bi2Sr2−xCsxCo2Oy materials with 0 ≤ x ≤ 0.15, have been fabricated via the classical ceramic technique. XRD results have indicated that undoped and Cs-substituted samples are composed of Bi2Sr2Co2Oy phase as the major one. Microstructural studies have demonstrated the formation of a liquid phase, which allows a drastic grain growth. This factor is responsible for a drastic improvement of relative density, reaching about 95% of the theoretical one for 0.125 Cs content. On the other hand, electrical resistivity has been reduced up to 14 mΩ cm at 650 °C for 0.125 Cs content, around 40% lower than the obtained in undoped samples. As a consequence, Seebeck coefficient has been decreased due to the raise in charge carrier concentration. The highest power factor at 650 °C (0.21 mW/K2 m) has been found for 0.125 Cs substituted sample, about 40% larger than the obtained in undoped samples, and very similar to the notified in single crystals (0.26 mW/K2 m). Magnetisation with respect to temperature results have demonstrated that measured samples have a paramagnetic property above 50 K, except 0.10 Cs. Magnetic hysteresis curves have shown that the slopes and the magnitudes have increased with decreasing temperature.

Controlled Synthesis and Properties of 3d–4f Metals Co-doped Polyoxometalates-Based Materials

It is challenging to explore and prepare polyoxometalates-based nanomaterials (PNMs) with controllable morphologies and diversiform components. Herein, 3d–4f metals are introduced into isopolyoxometalates and Anderson-type polyoxometalates, CeCdW12 nanoflower and EuCrMo6 microflaky have been fabricated respectively. A series of control experiments are carried out to identify the impact factors on the rare morphologies in PNMs. Furthermore, upon excitation at 396 nm, the emission spectrum of EuCrMo6 displays five prominent f − f emitting peaks at 674, 685, 690, 707, and 734 nm that are assigned to Eu3+ 5D0 → 7FJ (J = 0, 1, 2, 3, 4) transitions. Meanwhile, the VSM results show that the Cr+3 ions in EuCrMo6 display anti-ferromagnetic interactions when the temperature is lower than − 17.54 K. After rising temperature, this material exhibits paramagnetic property. This work opens up strategies toward the brand new morphologies and components of PNMs, endowing this kind of material with new functions.

Preparation and Characterization of Paramagnetic Bis (8-Hydroxyquinoline) Manganese Crystals

The magnetic properties of π-conjugated bis (8-hydroxyquinoline) manganese (Mnq2) crystals are investigated. Rod-shaped Mnq2 crystals are prepared by using the physical vapor deposition method. Field emission scanning electronic microscopy spectra show that the Mnq2 nanorods have perfect plane quadrangular ends. Energy dispersive spectrometer and X-ray photoelectron spectroscopy analysis demonstrates that the powders and nanorods are the same compound with a high purity. X-ray diffraction analysis shows the high crystal quality of the prepared Mnq2 nanorods. The magnetic measurement, using alternating gradient magnetometer and magnetic property measurement system superconducting quantum interference device vibrating sample magnetometer, indicates that the prepared Mnq2 nanorods show a paramagnetic property at room temperature. First-principles density functional theory (DFT) calculations are used to study the electronic structure and magnetic properties of the prepared Mnq2 crystals. DFT calculations show that the magnetic moment of the Mnq2 isolated molecule is 5 μB, which mainly comes from the localized Mn 3d orbital. The energy difference between the antiferromagnetic and ferromagnetic states of the Mnq2 monoclinic cell is only 0.1 meV, which may explain the paramagnetic property observed in the prepared Mnq2 nanorods and also indicates the difficulty of preparing intrinsic ferromagnetic Mnq2 crystals.

Synthesis of perovskite-type manganites Yb1−xDyxMnO3 (0.1 ≤ x ≤ 0.5) via solid-state reaction and high-pressure flux methods followed by structural characterization and magnetic property studies

h-Yb1−xDyxMnO3 (0.1 ≤ x ≤ 0.5) and single crystal o-Yb0.5Dy0.5MnO3 were firstly synthesized, and o-Yb0.5Dy0.5MnO3 has the paramagnetic property due to slight structural difference.