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T. V. Machaidze

Publications and source records attributed to T. V. Machaidze.

7 recordsLinked to original sources
arXiv2008

Temperature dependence investigation of dissipation processes in strongly anisotropic high-temperature superconductors of Bi-Pb-Sr-Ca-Cu-O system synthesized using solar energy

The investigation of temperature dependence of damping and period of vibrations of HTSC superconductive cylinder of Bi-Pb-Sr-Ca-Cu-O system suspended by a thin elastic thread and performing axial-torsional vibrations in a magnetic field at temperatures above the critical one for the main phase Tc=107 K were carried out. It was observed some "chaos" temperature region in the temperature interval 107-138 K, where it is seen separate ripples of dissipation and oscillation frequency. It is assumed that the "chaos" region could point to a possibility of existence of other magnetic and more high-temperature phases as single islands in a normal materials matrix.

cond-mat.supr-con↗
arXiv2008

Investigation of stimulated dynamics in strongly anisotropic high-temperature superconductors system Bi-Pb-Sr-Ca-Cu-O

It is used the mechanical method of Abrikosov vortex stimulated dynamics investigation in superconductors. With its help it was studied relaxation phenomena in vortex matter of high-temperature superconductors. It established that pulsed magnetic fields change the course of relaxation processes taking place in vortex matter. The study of the influence of magnetic pulses differing by their durations and amplitudes on vortex system of strongly anisotropic high-temperature superconductors system Bi1.7Pb0.3Sr2Ca2Cu3O10-d showed the presence of threshold phenomena. The small duration pulses do not change the course of relaxation processes taking place in vortex matter. When the duration of pulses exceeds some critical value (threshold), then their influence change the course of relaxation process which is revealed by stepwise change of relaxing mechanical moment.. These investigation showed that the time for formatting of Abrikosov vortex lattice in Bi1.7Pb0.3Sr2Ca2Cu3O10-d is of the order of 150 us which on the order of value exceeds the time necessary for formation of a single vortex observed in isotropic high-temperature superconductor HoBa2Cu3O7-d and on two orders exceeds the creation time of a single vortex observed in classical type II superconductors.

cond-mat.supr-con↗
arXiv2007

Investigation of relaxation phenomena in high-temperature superconductors HoBa2Cu3O7-d at the action of pulsed magnetic fields

It is used the mechanical method of Abrikosov vortex stimulated dynamics investigation in superconductors. With its help it was studied relaxation phenomena in vortex matter of high-temperature superconductors. It established that pulsed magnetic fields change the course of relaxation processes taking place in vortex matter. The study of the influence of magnetic pulses differing by their durations and amplitudes on vortex system of isotropic high-temperature superconductors system HoBa2Cu3O7-d showed the presence of threshold phenomena. The small duration pulses does not change the course of relaxation processes taking place in vortex matter. When the duration of pulses exceeds some critical value (threshold), then their influence change the course of relaxation process which is revealed by stepwise change of relaxing mechanical moment . These investigations showed that the time for formatting of Abrikosov vortex lattice in HoBa2Cu3O7-d is of the order of 20 microsec. which on the order of value exceeds the time necessary for formation of a single vortex observed in type II superconductors.

cond-mat.soft↗
arXiv2005

Investigation of the anisotropy of dissipation processes in single crystal of Yba2Cu3O7-d system

By means of contactless mechanical method of the measurement of energy losses in superconductors, the anisotropy of dissipation processes has been studied in single crystal high-temperature layered superconductors of Yba2Cu3O7-d system, being in mixed state. The observed anisotropy of energy losses indicates the possibility of the existence of the symmetry of order parameter of dx2-y2 type in these single crystals.

cond-mat.supr-con↗
arXiv2005

Investigation of stimulated dynamics of vortex-matter in high-temperature superconductors

A simple mechanical method for the investigation of Abrikosov vortex lattice stimulated dynamics in superconductors has been used. By this method we studied the action of pulsed magnetic fields on the vortex lattice and established the resulting change of the course of relaxation processes in the vortex matter in high-temperature superconductors. This method can be used for investigation of phase transitions in vortex matter both high-temperature and exotic superconductors.

cond-mat.supr-con↗
arXiv2001

3D-2D phase transition in vortex lattice of layered high-temperature superconductors of BSCCO (Bi$_{1.7}$Pb$_{0.3}$Sr$_2$Ca$_2$Cu$_3$O$_4$)

Using the high-sensitive mechanical method of measuring the dissipation processes in superconductors, the 3D-2D phase transition in magnetic field was investigated in the vortex lattice of strongly anisotropic high-temperature superconductors of Bi(2223) system. It was shown that with the increase of external magnetic field the dissipation connected with a motion of vortexes relative to the crystal lattice of a sample, first increases, reaching the maximum and then with a further increase of the magnetic field sharply reduces as a result of pinning enhancement in connection with the transition of three-dimensional vortex system in quasi-two-dimensional "pancake" one.

cond-mat.supr-con↗