Photo-induced "high-temperature" superconductivity of multicomponent metal-oxide compounds

The work is devoted to the problem of searching for substances with superconductivity at room temperature and atmospheric pressure. It develops ideas in the direction of studying the properties of multicomponent metal-oxide compounds. The main attention is paid to studies devoted to explanation of the role of various mechanisms of the formation of paired electrons in these compounds. Naturally, most of this kind of research is devoted to the study of the chemical structure and crystallographic structure of metal oxides, since they determine the properties of the electronic subsystem of these substances, which cause their transition to the superconducting state. Analysis of the crystallographic structure of metal oxide YBa2Cu3O7–х leads to the conclusion that the main role in the formation of its superconducting state is played by the presence of planes CuO2, separated by solitary planes composed of chains CuO.  The presence of chemically different states of like-named pairs of ions, characterized by different types of bonds (ionic and covalent), as well as the specific layered crystallographic structure of the metal-oxide give rise to the existence of clusters of negative U-centers capable of generating paired electrons realizing the superconductivity of metal-oxide substances. This paper discusses the possibility of intensifying the transition of metal-oxide compounds to the superconducting state under conditions of irradiation with a photon flux. In this case, the formation of an energy spectrum that allows local pair transitions of electrons can be activated (the effect of internal photoionization) and, thus, the transition of metal oxides to the superconducting state can occur at higher temperatures than is observed under normal conditions

Creep of the Ti₃AlC₂ MAX-phase ceramics

The process of plastic deformation of multicomponent ceramics based on the MAX phase at room temperature and at higher (1000 °C) temperature has been studied by dilatometry and microindentation. Based on the experimentally obtained dependence of the strain rate of the material on the magnitude of the applied load, conclusions were made about the mechanisms controlling the plastic deformation process in the samples under study

Thermal and crack resistance of ceramics based on the MAX phase Ti₃AlC₂

The paper discusses the conditionality of such physical properties of polycomponent oxygen-free ceramics (MAX phases), as thermal and fracture resistance, with a special physicochemical nature of the binding forces between the elements forming the MAX phase and with a specific structural state characterized by the presence of thin interlayer between the structure elements with an unordered arrangement of atoms. The results of the experimental study of some of the physical properties of Ti₃AlC₂-based materials are presented, which are consistent with the proposed concept