Goulatis I. Transport anisotropy, excess conductivity and structural relaxation in HTSC single crystals of the 1-2-3 system

Object of research: Structural parameters, and also temperature, concentration, time, field and baric dependences of resistivity parameters of HTSC single crystals of the 1-2-3 system. Aim: dynamic phase transitions and features of reciprocal of localization processes, fluctuation and pseudo-gap anomalies in the conditions of action of external factors (low temperature, high pressure and magnetic field), and also structural anisotropy and given defects topology of crystalline grate in HTSC- compounds of the 1-2-3 system. Results, novelty:1. For the first time it is determined that, the boundaries of the twin domains are effective centers for the scattering of normal carriers. With the reduction of the oxygen content, there is an increase of the processes of the carrier localization. This in turn accompanies the transition from a pseudo-gap regime to the variable-range-hopping regime. 2.For the first time it is shown that energy of activation of relaxation process of electroresistance of oxygen deficient ReBaCuO (Re=Y, Ho) single crystals is temperature and pressure function. It is thus established, that as approaching an equilibrium condition in system the size of energy of activation and characteristic times of processes of a relaxation increase. 3. For the first time it is established, that the appendix of a constant magnetic field to 12,7 kOe in weak doped by aluminium YBaCuAlO single crystals leads to essential narrowing of a temperature interval of exess paraconductivity. The excess conductivity shows exponential temperature dependence and can be interpreted in the mean field theory, where Т* represents the mean field crossover temperature to a pseudogap regime. Application field:solid state physics, superconductivity.