Related papers: Thin superconducting disk with field-dependent cri…
We have studied the nucleation of superconductivity in a mesoscopic Al disk wit a Co/Pd magnetic dot placed on the top by measuring the normal superconducting phase boundary Tc(B). The measurements have revealed a pronounced asymmetry with…
We present transport critical current measurements on microfibers consisting of a 80-nm thick layer of polycrystalline MgCNi3 synthesized directly onto 7-micron diameter carbon fibers. Near the transition temperature, Tc, the critical…
A rapid decrease in the critical current density (Jc) of YBa2Cu3O7-x (YBCO) films with increasing film thickness has been observed for multiple YBCO growth processes. While such behavior is predicted from 2D collective pinning models under…
We report a detailed set of AC magnetic measurements carried out on bulk large grain La-Ca-Mn-O samples extracted from a floating zone method-grown rod. Three samples with $La_{0.78}Ca_{0.22}Mn_{0.90}O_{x}$ stoichiometry but differing in…
Creating complex flux configurations by superposing a dc current or magnetic field onto the ac current in a type II superconducting tape should lead to a variety of peculiar behaviors. An example is the appearance of the Clem valley, a…
A transport current distribution over a wide superconducting sheet is shown to strongly change in a presence of bulk magnetic screens of a soft magnet with a high permeability. Depending on the geometry, the effect may drastically suppress…
Electrical resistivity experiments show superconductivity at $T_c = 1.1\,$K in a high-quality single crystal of trigonal $\gamma$-PtBi$_2$, with an enhanced critical magnetic field $\mu_0H_{c2}(0) \gtrsim 1.5\,$Tesla and a low critical…
From a very simple description of vortices and pinning centers and without using any electrodynamical assumptions, we obtain nonlinear density profiles of vortices in type-II dirty superconductors that result from raising or lowering an…
Stacks of superconducting tapes can trap much higher magnetic fields than conventional magnets. This makes them very promising for motors and generators. However, ripple magnetic fields in these machines present a cross-field component that…
Superconducting accelerator magnets have a nonlinear dependence of field on current due to the magnetization associated with the iron or with persistent currents in the superconducting filaments. This also gives rise to hysteresis phenomena…
In type-I superconductors, zero electrical resistivity and perfect diamagnetism define two fundamental criteria for superconducting behavior. In contrast, type-II superconductors exhibit more complex mixed state physics, where magnetic flux…
We present a study of the magnetic response of Type-II superconductivity in the extreme pinning limit, where screening currents within an order of magnitude of the Ginzburg-Landau depairing critical current density develop upon the…
Extensive measurements of the magnetization of superconducting single crystal samples of Ba0.6K0.4BiO3} have been made using SQUID and cantilever force magnetometry at temperatures ranging between 1.3 and 350 K and in magnetic fields from…
The complex magnetic transitions and superconductivity of HoNi2B2C were studied via the dependence of the heat capacity on temperature and in-plane field angle. We provide an extended, comprehensive magnetic phase diagram for B // [100] and…
The dynamics of transient current distributions in superconducting YBCO thin films were investigated during and immediately following an external field ramp, using high-speed (real-time) Magneto-Optical Imaging and calculation of dynamic…
We present superconducting properties of single crystalline Ba(Fe$_{0.9}$Co$_{0.1}$)$_{2}$As$_{2}$ by measuring magnetization, resistivity, upper critical field, Hall coefficient, and magneto-optical images. The magnetization measurements…
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…
We report the magnetoresistance of high-quality single crystals of UTe2 with Tc=2.1K in high magnetic fields up to 36T, with the field direction between the b and c-axes. From the angular dependence of the upper critical field Hc2, we found…
The intergranular pinning potential U and the critical current density Jc for polycrystalline RuSr2Gd1.5Ce0.5Cu2O10 ruthenate-cuprate were determined at zero magnetic field and temperature through the frequency shift in the peak of the…
The surprisingly rapid relaxation of the sustainable current density in the critical state of single crystalline Ba$_{1-x}$K$_{x}$Fe$_{2}$As$_{2}$ is investigated for magnetic fields oriented parallel to the c-axis and to the $ab$--plane…