Spin and charge fluctuations in solid solutions of titanium substitution by iron group metals

Abstract

Topological electronic transitions from omega- to alpha-phase and from alpha- to beta-phase that occur with an increase in the concentration of substitution atoms in solid solutions of titanium with iron group metals are considered. It is found that due to the difference in the potentials of the Hubbard repulsion of titanium and substitution atoms, as well as temperature Bose excitations, spin and charge fluctuations of the electron density increase in the topological alpha phase. Accounting for fluctuations makes it possible to describe the concentration increase in the entropy of the phases of the titanium alloys under consideration at different temperatures. The amplification of electronic fluctuations with increasing temperature and concentration shifts the chemical potential beyond the topological area of the electronic spectrum, thereby suppressing the alpha phase and inducing an electronic transition to the beta phase. Using the example of calculations of the entropy of titanium substitution alloys with iron at different temperatures, a diagram of their structural phases is constructed, which is consistent with the available experimental data. Keywords: solid solutions, topological electronic transitions, spin and charge fluctuations, entropy, structural phases.