Electronic Structure of V_xTi₁-_xSe₂ Solid Solutions with the (V,Ti)Se₂ Structural Fragments

The equilibrium boundary for the layered VxTi1-xSe2solidsolution was determined according to a set of experimental data of synchrotronradiation X-ray photoelectron spectroscopy and electromotive force of the Li|Li+|VxTi1-xSe2electrochemical cells. This boundary appears to be 20 mol % ofV(x= 0.2). The formation of the VSe2structural fragments, which are tightlybounded with VxTi1-xSe2layers, appears atx> 0.2. A combined analysis of theFermi-surface maps and the atomic force microscopy images reveals that the(001) planes in VSe2and VxTi1-xSe2structural fragments are parallel to eachother. At the same time, these fragments demonstrate turbostratic disorderingwithin the basal plane. The formation of such pseudo-homogeneous materialsis associated with the contribution of the free surface energy, which is relativelyhigh in the quasi-two-dimensional materials