相关论文: Flux Creep and Flux Jumping
A theoretical study of dynamics of small thermal and electromagnetic perturbations in type-II superconductors in the flux creep regime with a nonlinear current-voltage characteristics is performed. For this purpose, the space-time evolution…
Numerical studies of the flux creep in superconductors show that the distribution of the magnetic field at any stage of the creep process can be well described by the condition of spatial constancy of the activation energy $U$ independently…
The understanding of flux jumps in the high temperature superconductors is of importance since the occurrence of these jumps may limit the perspectives of the practical use of these materials. In this work we present the experimental study…
In this work we present the results of the bulk magnetization measurements in a superconducting state of single crystals of Ba$_{0.65}$Na$_{0.35}$Fe$_2$As$_2$. The isothermal magnetic field ($H||c$ axis) dependent magnetization ($M$) loops…
Type II superconductors can trap a transient magnetic field and become "cryomagnets" that are very useful for applications. During this process, flux jumps i.e. sudden jumps of the total magnetization occur and hinder the properties of…
We consider the current density distribution function of a flux creep regime in type-II superconductors by mapping the flux creep process to the dynamics of a model with a self-organized criticality. We use an extremal Robin Hood type model…
Magnetic flux jumps in textured Bi2Sr2CaCu2O(8+d) have been studied by means of magnetization measurements in the temperature range between 1.95 K and Tc, in an external magnetic field up to 9 T. Flux jumps were found in the temperature…
We studied the critical state stability in a large cubic sample of a single crystalline La(1.85)Sr(0.15)CuO(4) for different sample orientations with respect to the external magnetic field as well as the dynamics of the flux jumps. It is…
We study theoretically the space-time evolution of the thermal and electromagnetic perturbation in a superconductor with a nonlinear current-voltage characteristics in the flux creep regime. On the basis of a linear analysis of a set of…
A theoretical study of small thermal and electromagnetic perturbations in type-II superconductors is studied in the flux creep regime with a power-law voltage-current characteristics. The space-time evolution of temperature and electric…
Magnetic flux distribution across a high-temperature superconductor strip is measured using magneto-optical imaging at 15 K. Both the current-carrying state and the remanent state after transport current are studied up to the currents 0.97…
The flux creep problem for a superconductor slab placed in a constant or time-dependent magnetic field is considered. Logarithmic dependence of the activation energy on the current density is assumed, U=U0 ln(J/Jc), with a field dependent…
We discuss predictions of five proposed theories for the critical state of type-II superconductors accounting for both flux cutting and flux transport (depinning). The theories predict different behaviours for the ratio $E_y/E_z$ of the…
Flux-creep data was obtained for fields along the second magnetization peak observed in M(H) curves of BaFe{1.9}Ni{0.1}As2 for H||c-axis. H||ab-planes and H forming a 45 degrees angle with ab-planes. The M-H loops from the different field…
In the mixed state of layered superconductor the antiferromagnetic order of magnetic ions can create the spin-flop domains along the phase cores of the Josephson vortices. The paper discusses how this feature affects the macroscopic quantum…
The flux trapping that occurs in the process of cooling down of the superconducting cavity is studied. The critical fields $B_{c2}$ and $B_{c1}$ depend on a position when a material temperature is not uniform. In a region with $T\simeq…
Magnetothermal instabilities are one of the peculiar phenomena of interest in conventional type-II, as well as in high-$T_c$ superconductors. In the present paper we attempt to analyze the nature and origin of the magnetothermal…
We predict a novel buckling instability in the critical state of thin type-II superconductors with strong pinning. This elastic instability appears in high perpendicular magnetic fields and may cause an almost periodic series of flux jumps…
The flux jump dynamics in the flux flow regime of type II superconductors is investigated, analytically. It is found that under some conditions flux jump avalanche may occur in a superconductor sample, which takes into account an inertial…
Vortex dynamics in a multiband anisotropic superconducting such as the Fe based superconductors, is interesting and potentially important for applications. In this study we examine flux-creep data for fields along the second magnetization…