相关论文: Interaction between superconductor and ferromagnet…

Magnesium diboride superconducting wires give the largest critical current density (Jc) when produced with iron sheath. Because iron is ferromagnetic, it is expected to improve the field dependence of Jc by shielding of the external field…

Transport critical current (Ic) was measured for Fe-sheathed MgB2 round wires. A critical current density of 5.3 x 10^4 A/cm^2 was obtained at 32K. Strong magnetic shielding by the iron sheath was observed, resulting in a decrease in Ic by…

Transport critical current (Ic) was measured for MgB2/Fe round wires, with magnetic field oriented perpendicular to the wire and parallel to it. Measurements were made on a wire with pure MgB2 core and another wire where MgB2 core was doped…

We theoretically predict that the critical current $I_c$ and magnetization $M$ of hybrid superconductor/normal-metal (SN) strip may have nonmonotonous dependence on perpendicular magnetic field - so called peak effect. In contrast to…

Local magneto-optical imaging and global magnetization measurement techniques were used in order to visualize shielding effects in the superconducting core of MgB_2 wires sheathed by ferromagnetic iron (Fe). The magnetic shielding can…

Magnetic measurements carried out on MgB_2 superconducting round wires have shown that the critical current density J_c(B_a) in wires sheathed by iron can be significantly higher than that in the same bare (unsheathed) wires over a wide…

The magnetic field $B$ dependence of the critical current $I_c$ for the vortex phase of a disordered superconductor is studied numerically at zero temperature. The $I_{c}(B)$ increases rapidly near the upper critical field $B_{c2}$ similar…

We have studied the phase diagram of MgB$_2$ superconductor using a single crystal for ${\bf H}\parallel c$-axis. For the first time we report the existence of peak effect in the screening current in MgB$_{2}$ single crystal for ${\bf…

Monofilamentary MgB2-wires with a mechanical tough Nb/Cu/steel or Fe/steel sheath were prepared and characterized. The steel content was varied to investigate the reinforcement effect and the consequences for the superconducting properties…

We investigate the Josephson critical current $I_c(\Phi)$ of a wide superconductor-normal metal-superconductor (SNS) junction as a function of the magnetic flux $\Phi$ threading it. Electronic trajectories reflected from the side edges…

We investigate the Josephson effect in S$_{\rm F}$XS$_{\rm F}$ junctions, where S$_{\rm F}$ is a superconducting material with a ferromagnetic exchange field, and X a weak link. The critical current $I_c$ increases with the (antiparallel)…

We report magnetic torque measurements on iron-pnictide superconductors Ba$_{1-x}$K$_x$Fe$_2$As$_2$ ($x \approx$ 0.69 and 0.76) up to an applied field of $B_a$ = 45 T. The peak effect is observed in torque-vs-field curves below the…

Recent theoretical and experimental research on low-bulk-pinning superconducting strips has revealed striking dome-like magnetic-field distributions due to geometrical edge barriers. The observed magnetic-flux profiles differ strongly from…

We have used small-angle-neutron-scattering (SANS) and ac magnetic susceptibility to investigate the global magnetic field H vs temperature T phase diagram of a single crystal Nb in which a first-order transition of Bragg-glass melting…

The critical current density Jc in high-Tc superconductors (HTS) often shows a maximum at field far above the self-field. We study this peak effect(PE) with the nonlinear I-V response of type-II superconductors and find analytical equation…

We study the effects of an external magnetic field on thensuperconducting phase diagram of a quasi-two-dimensional system of Dirac electrons at an arbitrary temperature. At zero temperature, there is a quantum phase transition connecting a…

We study a magnetic proximity effect at superconductor (S) - ferromagnet (F) interface. It is shown that due to an exchange of electrons between the F and S metals ferromagnetic correlations extend into the superconductor, being dependent…

We investigate theoretically an interacting metallic wire with a strong magnetic field directed along its length and show that it is a new and highly tunable one-dimensional system. By considering a suitable change in spatial geometry, we…

We analyze the enhancement of the superconducting critical temperature of superconducting/ferromagnetic bilayers due to the appearance of localized superconducting states in the vicinity of magnetic domain walls in the ferromagnet. We…

Monofilamentary MgB2-wires with a 2- or 3-component sheath containing mechanical reinforcing stainless steel (SS) were prepared and characterized. In direct contact to the superconductor Nb, Ta or Fe was used. For a selection of samples…