Ignatyeva T. Features of an electronic spectrum and their influence on physical characteristics of transitional metals and alloys based on these metals

Object: electronic-topological transitions under the influence of different external factors. The purpose: an establishment of connection of the changes of physical properties of transition metals and alloys on their basis with features of an electronic spectrum. Methods: a technique of reception of high pressures, measurement of temperature of superconducting transition at 4,2K, a high-sensitivity technique of thermo electromotive measurement, ion channeling. Results: electronic-topological transition - formation of new electronic group in Mo under action of impurity Re is revealed. It is experimentally shown, that the change of topology of a Fermi surface at electronic-topological transition in alloys Mo-Re is accompanied by change of an energy condition of electrons in a narrow energy interval near a bottom of a zone which meets a new cavity of a Fermi surface. By means of a direct method of researches of crystal structures - ion channeling of helium in a crystal, connection of electronic transitions with formation of superstructure in crystal body-centered cubic cell to structure of a solid solution of alloys Mo1-x-Rex is established. Quantitative parameters of electronic-topological transitions in rhenium under influence of impurity of different valences are defined. It is shown that under the changes of topology of a Fermi surface it is necessary to consider not only changes of density of electronic conditions, but also changes of dynamics of electron movement. The field of application: physics of a solid state, the electrophysics, the physics of metals