Synthesis, spectroscopic and thermogravimetric interpretations of UO2(II), ZrO(II), Zr(IV), VO(II) and V(V) ciprofloxacin antibiotic drug complexes

New five ciprofloxacin (CIP) complexes of dioxouranium(II), oxozirconium(II), zirconium(IV), oxovanadium(II) and vanadium(IV) in the proportion 1:2 have been prepared using CIP as a drug chelate with UO2(NO3)2. 6H2O, ZrOCl2. 8H2O, ZrCl4, VOSO4. xH2O and V2O5 respectively. The CIP complexes have been characterized based on the elemental analysis, molar conductance, magnetic, (FTIR & 1HNMR) spectral and thermal studies. The molar conductance studies of the synthesized complexes in DMSO solvent with concentration of 10–3 M indicate their non-electrolytic properties. At room temperature, the magnetic moment measurements revealed a diamagnetic behavior for all CIP prepared complexes. The different formulas of the new complexes can be represented as [UO2(CIP)2(NO3)2] (I), [VO(CIP)2(SO4)(H2O)] (II), [V2(O)(O2)2(CIP)2] (III), [Zr(O)(CIP)2(Cl)2] (IV), and [Zr(CIP)2(Cl)4] (V). The thermal analysis data of the complexes indicates the absence of coordinated water molecules except for vanadyl(II) complex (II). The CIP chelate is a uni-dentate ligand coordinated to the mentioned metal ion through terminal piperazinyl nitrogen. The transmission electron microscopy (TEM) investigation confirms the nano-structured form of the complexes.

The Dependence of Magnetic Moments on Magnetic Impurities of Ni in Eu1.86Ce0.14Cu1-yNiyO4+a-d

The partially substitution of magnetic impurity Ni for Cu in electron-doped superconducting cuprates of Eu2-xCexCu1-yNiyO4+a-d with x = 0.14 and y = 0, 0.01 and 0.02 has been studied in order to investigate the effect of Ni impurity on structure and the value of magnetic moments per unit volume extracted from susceptibility data in under-doped region. Magnetic-susceptibility measurements were carried out at low temperatures down to 2 K. For sample with y = 0, diamagnetic behavior is observed starting from about 9 K. The superconductivity disappeared at y ³ 0.01. The values of magnetic moment in every volume unit decreased with increasing Ni.

Structure and Magnetic Properties of Eu2-xCexCu1-yNiyO4+α-δ

Electron-doped superconducting cuprates of Eu2-xCexCu1-yNiyO4+a-d in under-doped region with x = 0.12 and y = 0, 0.01, 0.02, 0.03 and 0.05 have been prepared, characterized and investigated in order to study the effect of Ni impurity to the magnetic properties of electron doped superconducting cuprates. All main peaks of tetragonal and T’ structure configuration of ECCO were observed in all samples. Temperature dependence of dc magnetic-susceptibility on field cooling at 5 Oe for Eu1.88Ce0.12Cu1-yNiyO4+a-d with d values from 0.0496 to 0.08322 shows diamagnetic behavior for sample with y = 0, starting from about 11 K. For sample with y = 0.01, Tc onset decreases to be around 4 K. The superconductivity disappeared at y ≥ 0.02 indicating 2 % Ni substitution to the Cu has weakened the spin-spin correlation and reduced the value of magnetization in ECCO system.

Crystal Growth and Physical Properties of Lu(Al1-xTx)B4 (T = Fe, Cr) by Al-Self Flux

Crystals of the quaternary compounds α-Lu(Al1-xTx)B4(T = Fe, Cr) (YCrB4-type, orthorhombic, Pbam), obtained from the nominal composition of Lu(Al1-xTx)B3, were grown by using Al flux mixed with T metal at 1773 K for 5 h under an Ar atmosphere. The maximum dimensions and morphology of the crystals obtained were about 0.7 mm × 0.5 mm for flake-type crystals of Lu(Al1-xCrx)B4and about 5.2 mm × 0.2 mm for prism crystals of Lu(Al1-xFex)B4. The lattice constants determination and chemical analyses of Lu(Al1-xTx)B4(T = Fe, Cr) compounds were carried out for Fe 0.5 - 10.0 at% and Cr 0.5 - 1.0 at%. The lattice constants and the unit lattice volume in Lu(Al1-xTx)B4crystals decreased with increase of the concentration of Fe or Cr. The values of micro-Vickers hardness of Lu(Al1-xFex)B4(x = 0.005 - 0.030) and Lu(Al1-xCrx)B4(x = 0.005 - 0.010) samples are in the ranges of 16(2) - 20(3) GPa and 13(2) - 16(3) GPa, respectively. The hardness values showed a little increase as the solid solution of Fe or Cr was realized in Lu(Al1-xTx)B4, possibly because of distortion to the crystal structure. The magnetic susceptibility of as-grown Lu(Al0.995Fe0.005)B4crystals for example, exhibited diamagnetic behavior with a small ferromagnetic component.

Magnetic excitations of carbon nanotubes in chiral model of graphene

Within the scope of the chiral model of graphene in 8-spinor realization, suggested earlier [1, 2], the combined spinor field Ψ is used as a new order parameter, which contains information on spin and quasispin excitations in graphene (8-spinor part) and also that on sp-hybridization effect of carbon valence electrons [SU(2)-matrix part]. This model admits two kinds of configurations describing, in the long-wave approximation, the graphene mono-atomic plane and the carbon nanotube respectively. The first one is given by the domain-wall (or kink-like) solution and the second one is described by the hedgehog ansatz with large topological charge (winding number n). We consider the infinite carbon nanotube in a static external magnetic field oriented along the tube and analyze the structure of the magnetic intensity on the outside. The diamagnetic behavior of the material is shown by the perturbation method which proves to be self-consistent for n ≫ 1.

Influence of precursor type on structural, morphological, dielectric and magnetic properties of TiO2 nanoparticles

TiO2 nanoparticles (NPs) were synthesized by sol-gel methods using two different precursors, titanium tetraisopropoxide and potassium titanium oxalate (KTO). The precursors had a profound influence on the structural, morphological, dielectric and magnetic properties of synthesized TiO2 NPs, as evidenced by the XRD, FE-SEM, TEM, LCR and VSM studies in the synthesized samples. Alkoxide-derived TiO2 NPs contained mostly mixed phases of anatase and rutile, whereas KTO-derived TiO2 NPs contained anatase and Magnéli phases (TinO2n-1). After heat treatment at 550 °C, the crystallite size of KTO-derived NPs was lower than alkoxide-derived TiO2 NPs. The synthesized nanoparticles were spherical and agglomerated having anatase and rutile phases with different proportions in the microstructure of the alkoxide sample. Dielectric constant of the KTO-derived NPs was higher than the alkoxide-derived NPs. Diamagnetic behavior of KTO-derived NPs was also higher than the alkoxide-derived TiO2 NPs.