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An X-ray image registration system that consists of a detector that contains two microchannel plates (MCPs), an optical lens, and a digital video camera is presented. Images of the K-spectra of Ca, Ti, Mn, Fe, and Co were obtained using an X-ray fluorescence spectrometer with a curved quartz crystal and horizontal focusing by the Johann method. Measurements were performed using detectors with gain coefficients of 106 and 107 and two video cameras with different characteristics and pixel sizes. A high speed of spectrum measurements with acceptable statistics has been achieved. The spectrum measurement was duplicated on a one-dimensional position detector. [ABSTRACT FROM AUTHOR]

An experimental study of the electronic structure of copper intercalated titanium dichalcogenides in a wide range of copper concentrations (x = 0.04-0.8) using x-ray photoelectron spectroscopy, resonant photoelectron spectroscopy, and x-ray absorption spectroscopy has been performed. Shift towards low energies of the Ti 2p and Se 3d core level spectra and a corresponding decrease in the photon energy of Ti 2p absorption spectra with the increase in copper concentration have been found. These sign-anomalous shifts may be explained by the shielding effect of the corresponding atomic shells as a result of the dynamic charge transfer during the formation of a covalent chemical bond between the copper atoms and the TiSe2 matrix. [ABSTRACT FROM AUTHOR]

Titanium is well known as a light-weight hydrogen storage material that is applied as a component of hydrogen storage composites together with Mg and other metals. Amorphous boron, boron nitride, and graphite were used as additives to improve Ti-H2 reactivity during ball-milling due to its anti-sticking and matrix-forming properties. The chemical state and local electronic structure of Ti atoms were studied by hard x-ray emission spectroscopy (XES). We have measured fluorescent Ti Kβ5 (4p→1s transition) x-ray emission spectra, which are very sensitive to the local surroundings of exciting atoms, and found additional features coinciding in energy with spectra of reference samples TiB2, TiN, and TiC. Based on these measurements, it is concluded that atoms of additives form chemical bonding with Ti due to the occupation of interstitials in the host Ti-lattice. [ABSTRACT FROM AUTHOR]

Abstract: We synthesize Cr x Ti1−x Se2 (x =0–0.83) and Cr x Ti1−x S2 (x =0.3–0.4) systems and study the structure of these materials on mono- and polycrystalline samples. It appeared that an increase in chromium content leads to inversion of titanium diselenide intercalated with chromium to chromium diselenide intercalated with titanium. The XPS of core levels and valence bands of 1T-Cr x Ti1−x Se2 and Cr x Ti1−x S2 was also investigated and it was shown that in in-layer and inter-layer positions the atoms of chromium and titanium are characterized by a slightly differing oxidation state. Chromium LDOS model calculations were carried out and the results being in agreement with the experimental data show that the Cr 3d density of electronic states of chromium in Ti-positions in the host lattice displays half-metallic properties, while the Cr 3d density of electronic states of intercalated chromium is far from being half-metallic. [ABSTRACT FROM AUTHOR]

Abstract: We have investigated the charge transfer characteristics and electronic structure of ferrocene-intercalated TiSe2. The spectroscopic results revealed that an intercalation of metallocene molecules leads to changes in the ionic valence of Fe atom in ferrocene molecule and the band gap, which is in accordance with electrical resistivity measurements showing metallic conductivity. Our analysis of 57Fe Mössbauer and Fe 2p XAS spectra suggested that the suppression of charge-density-wave state in TiSe2 and an appearance of metallic conductivity are attributed to charge transfer of electrons from ferrocene intercalant to the dichalcogenide host material. [ABSTRACT FROM AUTHOR]

This paper reports on the results of the experimental investigation into the angular dependence of the photoemission of the valence band (the angle-resolved photoelectron spectrum) for the Fe1/4TiTe2 single crystal upon excitation with circularly polarized radiation. The angle-resolved photoelectron spectrum is studied in the vicinity of the Γ point of the Brillouin zone in the two directions Γ K and Γ M with the highest symmetry. The measurements are performed in noncoplanar geometry. The circular dichroism in the photoemission angular distribution is observed over the entire ranges of energies and angles. The magnitude of the dichroism depends on the choice of the band, the binding energy, and the polar angle and varies from 0 at the Γ point to 20%. [ABSTRACT FROM AUTHOR]

The L 2, 3 spectra of titanium in the layered compound TiSe2 and intercalated compounds Fe1/2TiSe2, Cr1/3TiSe2, and Fe1/4TiTe2 are studied. Theoretical calculations of the electronic structure of these compounds are performed. The experimental data and calculations suggest that the intercalation of the Cr and Fe atoms into the TiSe2 matrix brings about a partial filling of the Ti 3 d states and the spin polarization of the Cr 3 d and Fe 3 d states. Chemical bonds are formed through the hybridization of the d orbitals of intercalated atoms with the Ti 3 d-Se 4 p states of the matrix. [ABSTRACT FROM AUTHOR]

The concentration dependences of the effective magnetic moment of transition metal atoms intercalated into TiSe2 are analyzed in the framework of the percolation theory. It is shown that, depending on the degree of localization of impurity states, the effective magnetic moment is determined by the overlap of 3 d orbitals of transition metals or orbitals of titanium atoms coordinated by impurity atoms. [ABSTRACT FROM AUTHOR]

An experimental study of the electronic structure of VxTi1-xSe2 system in a wide range of vanadium concentrations (x = 0.06-0.9) using x-ray photoelectron spectroscopy and resonant photoelectron spectroscopy has been performed. The partial charge transfer from the VSe2 to TiSe2 structural fragments is experimentally observed, and the most part of the charge is localized on the vanadium atoms in the VSe2 structural fragments. [ABSTRACT FROM AUTHOR]

The electronic structure of the ZrX2 (X = Se, Te) compounds has been studied using photoelectron, resonant photoelectron and X-ray absorption spectroscopy, theoretical calculations of the X-ray absorption spectra, and density of electronic states. It was found that the absorption spectra and valence band spectra are influenced by the chalcogen type. The results of the multiplet calculation of the Zr4+ atom show that the change in the splitting in the crystal field, which is described by the 10Dq parameter, is due to the change in the ratio of covalent and ionic contributions to the chemical bond. The resonance band near the Fermi level in the valence band spectra is observed for ZrTe2 in the Zr 3p-4d resonant excitation mode. The extent of photon energy indicates the charge localization on the Zr atom. Similar resonance band for ZrSe2 is absent; it indicates the presence of a gap at the Fermi level. [ABSTRACT FROM AUTHOR]

Results of X-ray fluorescence measurements of MA[sub 2]Ca[sub n-1]Cu[sub n]O[sub 2n+3] compounds with [M-12(n 1)n] type structures, (C[sub 0.8]N[sub 0.2]Sr[sub 2]CuO[sub 5.3], [Cu[sub 0.25](C,N)[sub 0.75]]Sr[sub 2]CaCu[sub 2]O[sub y], Cu[sub 0.5]V[sub 0.5]Sr[sub 2]CaCu[sub 2]O[sub 7.5], Cu[sub 0.5]V[sub 0.5]Sr[sub 2]Ca[sub 2]Cu[sub 3]O[sub 9.4], Cu[sub 0.5]V[sub 0.5]Sr[sub 2](Ca[sub 3.6]Sr[sub 0.4])Cu[sub 5]O[sub 13.5] and Cu[sub 0.5]V[sub 0.5]Sr[sub 2](Ca[sub 4.7]Sr[sub 0.3])Cu[sub 6]O[sub 15.3]), are presented. The experiments show that C-atoms form a distorted CO[sub 3] oxyacid group with a partial substitution of copper and nitrogen atoms in the M-sites. We conclude that the CO[sub 3, sup 2-] group in (C,N) Sr[sub 2]Ca[sub n-1]Cu[sub n]O[sub y] and (Cu,C,N) Sr[sub 2]Ca[sub n-1]Cu[sub n]O[sub y] is substituted by the NO[sub 2, sup -] which induces the creation of the hole carriers in these compounds. We have found that V-atoms in the given compounds form (VO[sub 4])[sup 3-] tetrahedrons and have a pentavalent state. [ABSTRACT FROM AUTHOR]