Structural and spectroscopic insights into the performance of KTb(PO) green phosphor.

A narrow-band green emitting KTb(PO) phosphor has been synthesized by a novel single-crystal growth approach involving the application of an inert flux. Its structural and spectroscopic peculiarities have been systematically studied by means of single-crystal X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy analysis, and diffuse reflectance, infrared and photoluminescence spectroscopy. The layered framework of the title compound is organized by linking together slightly distorted phosphate tetrahedra with non-condensed TbO polyhedra into [Tb(PO)] sheets interconnected by potassium cations.

Crystal growth, layered structure and luminescence properties of KEu(PO)(WO).

KEu(PO)(WO) has been prepared the high-temperature solution growth (HTSG) method using KWO-KPO molten salts as a self-flux and characterized by single-crystal X-ray diffraction analysis, IR and luminescence spectroscopy. The structure of this new compound features a 2D framework containing [EuPO] layers, which are composed of zigzag chains of [EuO] interlinked by slightly distorted PO tetrahedra. Isolated WO tetrahedra are attached above and below these layers, leaving space for the K counter-cations.

Band Gap Engineering and Trap Depths of Intrinsic Point Defects in RAlO (R = Y, La, Gd, Yb, Lu) Perovskites.

The possibility of band gap engineering (BGE) in RAlO (R = Y, La, Gd, Yb, Lu) perovskites in the context of trap depths of intrinsic point defects was investigated comprehensively using experimental and theoretical approaches. The optical band gap of the materials, , was determined via both the absorption measurements in the VUV spectral range and the spectra of recombination luminescence excitation by synchrotron radiation. The experimentally observed effect of reduction from ∼8.

Mn luminescence of Gd(Zn,Mg)BO pentaborate under high pressure.

The results of X-ray diffraction studies of the Gd(Mg,ZnMn)BO down-converting phosphor as a function of Mg-Zn composition are presented. The lattice parameters and unit cell volumes of GdMgZnMnBO pentaborates are examined. The relationships between the structure and optical properties of these materials are explicated based on the results of theoretical calculations of the energy structure.

Structural and optical properties of langbeinite-related red-emitting KSc(MoO)(PO):Eu phosphors.

The concentration series of langbeinite-related solid solutions KSc(MoO)(PO):Eu ( = 0.1, 0.2, 0.

Partial Substitution of Potassium with Sodium in the KTi(PO) Langbeinite-Type Framework: Synthesis and Crystalline Structure of KNaTi(PO).

The interaction of TiN with NaO-KO-PO melts was investigated at (Na+K)/P molar ratios of 0.9, 1.0, and 1.

Synthesis and Properties of the La Eu Ca VO (0 ≤ x, y ≤ 0.2) Compounds.

The La Ca VO and La Eu Ca VO (0 ≤ x, y ≤ 0.2) micro/nanosized powders were prepared by aqueous nitrate-citrate sol-gel synthesis. Phase composition of the sample depends on the x and y values.

Structural Modification of Single-Layer Graphene Under Laser Irradiation Featured by Micro-Raman Spectroscopy.

Confocal micro-Raman spectroscopy is used as a sensitive tool to study the nature of laser-induced defects in single-layer graphene. Appearance and drastic intensity increase of D- and D' modes in the Raman spectra at high power of laser irradiation is related to generation of structural defects. Time- and power-dependent evolution of Raman spectra is studied.

Mechanical, Dielectric, and Spectroscopic Characteristics of "Micro/Nanocellulose + Oxide" Composites.

The set of composite materials that consist of micro/nanocellulose and complex KEu(MoO)(PO) luminescent oxide particles was prepared. The composites were studied by means of scanning electron microscopy, XRD analysis, dilatometry, differential scanning calorimetry and thermogravimetric analysis, and dielectric and luminescence spectroscopy.Dependencies of density, crystallinity, relative extension, thermal extension coefficient, dielectric relaxation parameters, intensity and shape of photoluminescence bands on temperature, and content of oxide component were studied.

Ab Initio Computational Study of Chromate Molecular Anion Adsorption on the Surfaces of Pristine and B- or N-Doped Carbon Nanotubes and Graphene.

Density functional theory (DFT) computations of the electronic structures of undoped, B- and N-doped CNT(3,3), CNT(5,5) carbon nanotubes, and graphene with adsorbed chromate anions CrO were performed within molecular cluster approach. Relaxed geometries, binding energies, charge differences of the adsorbed CrO anions, and electronic wave function contour plots were calculated using B3LYP hybrid exchange-correlation functional. Oscillator strengths of electronic transitions of CrO anions adsorbed on the surfaces of studied carbon nanostructures were calculated by the TD-DFT method.

Structure and Optical Features of Micro/Nanosized Carbon Forms Prepared by Electrochemical Exfoliation.

Micro/nanosized carbon materials were prepared by electrochemical exfoliation method in the forms of the colloids and thin films. Scanning electronic microscopy, optical and luminescent microscopy, and Raman scattering and luminescent spectroscopy were applied for characterization of materials. The wide photoluminescence band in the visible spectral region was observed for each of the samples.

Thermal analysis of polyethylene + X% carbon nanotubes.

The aim of this research is to study the influence of the multi-walled carbon nanotubes (MWCNTs) on the thermomechanical and structural properties of high-density polyethylene. Several, complementary experimental techniques were used, namely, dilatometry, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Raman spectroscopy, and infrared (IR) spectroscopy. Dilatometry data showed that nanocomposites exhibit anisotropic behavior, and intensity of the anisotropy depends on the MWCNT concentration.

Lanthanide mixed-ligand complexes of the [Ln(CAPh)3(Phen)] and [LaxEu1-x(CAPh)3(Phen)] (CAPh = carbacylamidophosphate) type. A comparative study of their spectral properties.

A series of complexes Ln(Pip)3(Phen) (Ln(iii) = La, Ce-Nd, Sm-Lu, Y; HPip (CAPh type ligand) = 2,2,2-trichloro-N-(dipiperidin-1-yl-phosphoryl)acetamide, Phen = 1,10-phenanthroline) has been synthesized. The lanthanum(iii) doped europium(iii) complexes ([LaxEu1-x(Pip)3(Phen)], x = 0.99, 0.

Electronic structure and luminescence mechanisms in ZnMoO4 crystals.

Calculations of the band structure, partial densities of states and optical spectra of permittivity, reflectivity and absorption of perfect ZnMoO(4) crystal were performed using the full-potential linear-augmented-plane-wave method. It is shown that the calculated reflectivity spectra reproduce the main features of corresponding experimental spectra in the fundamental absorption region. The bandgap value of ZnMoO(4) is estimated as E(g) = 4.

Luminescent determination of automobile petrol in hexane solutions.

The work deals with the problem of determination of automobile petrol of various octane numbers and petroleum contamination of some objects on the basis of analysis of photoluminescence spectra of automobile petrol samples. For this purpose steady state luminescence properties of samples of automobile petrol of different types being in sale were measured. Samples of automobile petrol diluted in hexane were prepared and their luminescence spectra were measured at room and liquid nitrogen temperatures of samples.