Crystal Structure and Magnetic Properties A Nickel(II) Complex with 3-Hydroxyisonicotinic Acid Ligand

Crystal structure, microstructure and magnetic properties of Ni nanoparticles elaborated by hydrothermal route

Synthesis, crystal structure and ferromagnetic interactions of a novel nickel(II) complex involving nitroxide radicals

The normal state of high-Tc superconducting cuprates is crucial to understanding of the mechanism in superconductivity. There are two main ways to remove superconductivity so that the sample is in a normal state, that is by applying a large magnetic field or adding impurities such as Zn to the sample. To investigate the crystal structure and magnetic properties in the normal state of electron-doped high-Tc cuprates in overdoped regime, Eu2-xCexCu0.97Zn0.03O4+α-δ (ECCZO) with x = 0.16, 0.17, 0.18, and 0.19 has been synthesized by the solid-state reaction method. The crystal structure and magnetic properties of the samples were characterized by XRD and SQUID measurements. The results of XRD measurements shows all samples have T’-structure and the values of lattice parameters a, CuO bond length, and crystallite size increased with increasing x. On other hand, the value of lattice parameters c decreased with increasing x, causing the expansion of the tetragonal unit cell in the horizontal direction. From susceptibility measurements, in the normal state with 3% of Zn impurity all samples have the paramagnetic behaviour. The magnetic parameters of these samples analysed by the Curie law. With increasing of Ce concentration, the C and the are increased. The increase in the magnetic parameters since the increasing in magnetic ordering.

The cubic Ni3.3C carbide has been fabricated by mechanical alloying of elemental Ni powder and the multiwalled carbon nanotubes in a high energy planetary ball mill. Crystal structure of carbide obtained belongs to the defective structure of ZnS sphalerite type according to x-ray diffraction data. Parameters of the electronic structure of Ni3.3C were calculated by linearized muffin-tin orbitals method within the plane-wave approximation using as an input the defined parameters of crystal structure. Magnetic properties, such as temperature and field dependences of the magnetic susceptibility of Ni3.3C have been studied. Based on experimental data obtained by studying the crystal structure and magnetic properties of Ni3.3C, as well as on the basis of calculations of electronic structure parameters, a preferred displacement of the carbon atoms in tetrahedral voids of Ni crystal lattice has revealed.

The crystal structure and magnetic properties of a new dinuclear nickel(II) complex [LNi2(AcO)4]·14H2O, where L = 3,6,9,17,20,23-hexaazatricyclo [23.3.1.111,13] triaconta-1(29),11(30),12,14,25(26),27-hexene, has been studied. X-ray structure analysis shows that the compound consists of a discrete [LNi2(AcO)4] complex and 14 lattice water molecules. Each Ni atom is six coordinated by three N atoms from the macrocycle and three O atoms from the two coordinated acetates; two nickel atoms in each macrocycle are at the distance of 7.028A. The result of the magnetic measurement indicates that the zero-field splitting constant of nickel(II) centres |D| = 1.87 cm−1.

Our primary research goals are to synthesize, characterize, and study the structure, dimensionality, and physical properties of new highly correlated electron materials. Intermetallic lanthanide and oxide phases are of great interest due to their fascinating array of structural features and physical property phenomena, such as heavy fermion behavior, superconductivity, and magnetism. The crystal growth, structure, and physical properties of several different classes of materials, such as the Ln-M-Ga (Ln = La, Ce, Pr, M = Ni, Pd), Yb5Pt9, and R2Ir2O7 (R = Pr, Eu) compounds, will be highlighted within. The Ln-M-Ga phases allow us to examine the influence of the lanthanide environments, dimensionality and layering on the magnetic and transport properties in these compounds. For example, CePdGa6 is a heavy fermion with ã ~ 230 mJ mol-1 K-2 and exhibits an anisotropic magnetism with TN ~ 5.5 K. The structurally related compound, Ce2PdGa10, also shows enhanced mass behavior (ã ~ 220 mJ/mol- K2), exhibits paramagnetic behavior down to 2 K, and has a large positive MR > 200 % at 2 K and 9 T. Also bearing a striking resemblance to the CePdGa6 phase, Ce2PdGa12 is an antiferromagnetic heavy fermion with ã ~ 170 mJ mol-1 K-2 and a magnetic transition at TN ~ 11 K. The crystal structures and physical properties of several new Ln2NiGa10 (Ln = La, Ce, Pr) and Ln2NiGa12 (Ln = La, Ce, Pr) compounds will also be discussed and compared to determine the role of the lanthanide and transition metal environments. The oxide pyrochlores, R2Ir2O7 (R = Pr, Eu), which show geometrically frustrated magnetism, may also offer insight into the structure-property relationships in three dimensional materials.

Enhanced magnetic ordering by impurity Fe substitution on electron-doped superconductors Eu2-x+yCex-yCu1-yFeyO4+α-δ

Crystal structure and magnetic properties of cerium-doped YIG: Effect of doping concentration and annealing temperature

A series of pure phase YFeO3 sample powders doped with Eu3+ and Nd3+ were synthesized by sol-gel method. The influence of different ions doping on the crystal structure and magnetic properties of YFeO3 were investigated. The prepared sample powders were characterized by powder x-ray diffractometer, scanning electron microscope, energy dispersive spectrometer, Fourier transform infrared spectrometer, differential thermal analyzer and vibrating sample magnetometer. The results demonstrate that all sample powders are pure phase orthogonal perovskite structures, the crystal structure and the magnetization have changed. The lattice parameters and the saturation magnetization increases with the increase of ion radius or ion concentration in single doping system. In the case of double doping, the influence of the crystal structure and magnetic properties of YFeO3 is more complicated than that of single doping according to the change of ions concentration.

Deuterated potassium dihydrogen phosphate (DKDP) crystals with different deuterium contents have a wide range of applications, such as frequency conversion in high power lasers, electro-optic modulation, and Q-switching crystals for Pockels cells. However, there is a lack of systematic research on the effect of deuterium content on the fundamental structure and properties of these DKDP crystals. To this end, in this study, a series of DKDP crystals with different deuterium contents have been grown using the "point-seed" rapid growth method, and the structure and properties of the crystals have been characterized. The results indicate that as the deuterium content increases, the cell parameter along the a(b)-axis direction gradually increases, and the transmittance gradually increases in the infrared range. A small amount of doping (low H or D ratio) reduces the structural integrity of the crystal, and the crystals at intermediate deuterium concentrations have better crystallinity. The thermal properties of the crystals do no change significantly with the variation in the deuterium content. Overall, these findings can serve as a useful reference for boosting the application of DKDP crystals with various deuterium contents.

An end-on azido-bridged dinuclear nickel(II) complex [Ni2(L1)2(μ1,1-N3)2] · CH3COOH (I) and an end-on azido-bridged polynuclear copper(II) complex [CuL2(μ1,1-N3)] n , where L1 is the deprotonated form of 2-[(2-ethylaminoethylimino)methyl]-4-fluorophenol and L2 is the deprotonated form of 2-[(2- dimethylaminoethylimino)methyl]-4-fluorophenol, were prepared and characterized by elemental analysis and FT-IR spectra. Crystal and molecular structures of the complexes were determined by single crystal X-ray diffraction method (CIF files CCDC nos. 942641 (I) and 942642 (II)). Single crystal X-ray structural studies indicate that the Schiff base ligands coordinate to the metal atoms through phenolate oxygen, imine nitrogen, and amine nitrogen. The Ni atoms in the nickel complex are in octahedral coordination, and the Cu atoms in the copper complex are in square pyramidal coordination. Crystals of the complexes are stabilized by hydrogen bonds. The Schiff bases and the complexes showed potent antibacterial activities.

Crystal structure, microstructure and magnetic properties of SmCo-based films treated by different annealing methods

In this dissertation,�nickel(II) complexes featuring N4-Schiff base macrocycles�derived from diphenylamine-2,2'-dicarboxaldehyde (1-Ni and�2-Ni) with a new crystal structure ([2-Ni]Me)�were synthesized and investigated for electrochemical CO2 reduction (ECR). Cyclic voltammetry (CV) of two nickel complexes, 1-Ni and 2-Ni, illustrated the catalytic response whereas one, [2-Ni]Me, virtually remained peak-shaped in the presence of CO2,�indicating�the feasibility of ECR activity for these nickel complexes. To develop heterogeneous ECR catalysts in aqueous media, all nickel complexes were adhered on N-doped graphene (NG) through non-covalent interaction, obtaining Ni@NG hybrid catalysts. The Ni@NG catalysts showed satisfactory ECR activity with the faradaic efficiency of CO production (FECO) of 60-80% at the overpotential of 0.56 V vs. RHE. The ECR activity of Ni@NG catalysts�demonstrated�that the necessity of N-H functionality from the ligand is less important in the heterogeneous aqueous system owing to plenty of viable hydrogen-bond and proton donors from water and bicarbonate species. Besides, an unexpected formation of nickel complexes bearing acridine-based Schiff base ligand ([NiLACR]2+) was obtained�via the rearrangement of diphenylamine-2,2'-dicarboxaldehyde. In addition, electrochemical properties and hydrogen evolution reaction of the nickel complexes were preliminary investigated.

Crystal properties and interaction with flotation reagent of fluorapatite and dolomite

A high-quality Ag3SbS3 single crystal was grown by the Bridgman-Stockbarger method and its crystalline structure and homogeneity were investigated. The fundamental absorption edge of Ag3SbS3 was studied. The value of the band gap of the studied compound was obtained at the level of 1.91 eV at T = 300 K. The structural, electronic, and optical properties of the Ag3SbS3 crystal were considered within the framework of first-principles calculations using density functional theory (DFT). The structure of the crystal lattice was optimized and its closeness to the experimental one is shown. The band-energy structure of the crystal was calculated revealing that the crystal has a band gap of indirect type with Eg = 0.88 eV for GGA (0.35 eV for LDA). The origin of the energy bands in the crystal was clarified and the nature of the fundamental absorption edge was analyzed using the calculated density of electronic states. The dielectric function (real part ε1(ω) and imaginary part ε2(ω)) and absorption coefficient α(ω) were calculated for two independent directions in the crystal and compared with experimental data. The character and anisotropy of optical functions are analyzed. The high value of the absorption coefficient of the Ag3SbS3 crystal is shown, which makes it a promising material for use as an absorbing layer in photovoltaics.