Transformation of the crystal structure of NiTiSe under heating.

The crystal structure of the NiTiSe compound has been studied in the temperature range of 25-1000 °C using synchrotron radiation X-ray diffraction. The previously known order-disorder transition in the Ni sublattice at ∼100 °C was found to be a second-order phase transition and belongs to the 3D Ising universality class. Reversible extraction of nickel selenides was observed in the temperature range of 275-975 °C.

Electronic and Crystal Structure of New CrZrSe Intercalation Compounds.

New intercalation compounds CrZrSe were synthesized and thoroughly studied. Cr atoms were found to occupy the positions both tetrahedrally and octahedrally coordinated by the Se atoms in the interlayer gap. The magnetic properties and electrical resistivity were studied in the temperature ranges of 2.

Effect of the Titanium Self-Intercalation on the Electronic Structure of TiSe.

The effect of the superstoichiometric Ti intercalation on the electronic structure of TiSe was studied by using X-ray photoelectron spectroscopy in nonresonant and resonant modes along with the DOS (density of states) calculations. It was shown that the presence of the Ti atoms in the interlayer space leads to the formation of the Ti 3d/Ti 3d hybridized band between the Ti atoms in the regular lattice positions and Ti atoms in the interlayer space. The charge transfer to the conduction band was not observed in this case.

Specific features of the electronic structure of CoTiSe according to the resonant photoemission data.

The effect of atomic ordering in the cobalt sublattice on the electronic structure of the CoTiSe intercalation compounds has been studied using a complex of spectral techniques - XPS, XAS, and ResPES, along with theoretical calculations of the total and partial densities of states. It has been found that the cobalt intercalation significantly affects the character of the chemical bond inside the host lattice. No signs of the direct overlapping of the Co 3d orbitals in the ordered material were observed.

Electronic Structures of the Vanadium-Intercalated and Substitutionally Doped Transition-Metal Dichalcogenides TiVSe.

The electronic structures of V-intercalated TiSe and substitutionally doped dichalcogenides TiVSe have been studied using soft X-ray photoelectron, resonant photoelectron, and absorption spectroscopies. In the case of the substitution of Ti by V, the formation of coherently oriented structural fragments VSe and TiSe is observed and a small charge transfer between these fragments is found. Intercalation of the V atoms into TiSe leads to charge transfer from the V atoms to the Ti atoms with the formation of covalent complexes Ti-Se-V-Se-Ti.