Related papers: High-field magneto-optical imaging of superconduct…
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 distribution of magnetic field in single-phase polycrystalline bulk MgB2 has been measured using a Magneto-Optical (MO) technique for an external magnetic field applied perpendicular to the sample surface. The MO studies indicate that…
In high-quality c-axis-oriented MgB2 thin films, we observed high critical current densities (Jc) of 16 MA/cm^2 at 15 K under self fields comparable to those of cuprate high-temperature superconductors. The extrapolated value of Jc at 5 K…
The spatial distribution of a magnetic field can be determined with micrometer resolution using widefield nitrogen vacancy (NV) center magnetic imaging. Nevertheless, reconstructing the magnetic field from the raw data can be challenging…
Magnetic current imaging (MCI) is useful for non-destructive characterization of microelectronics, including both security analysis and failure analysis, because magnetic fields penetrate the materials that comprise these components to…
To address unsolved fundamental problems of the intermediate state (IS), the equilibrium magnetic flux structure and the critical field in a high purity type-I superconductor (indium film) are investigated using magneto-optical imaging with…
Prior to the onset of the ferromagnetic transition in semimetallic EuB_6, unusual magnetic and electric behavior have been reported. Using a highly sensitive magneto-optical imaging (MOI) technique, we visualize the behavior of magnetic…
Non-linear electrical transport studies at high-pulsed magnetic fields, above the range accessible by DC magnets, are of direct fundamental relevance to the physics of superconductors, domain-wall, charge-density waves, and topological…
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 theoretically investigate the response of a superconducting film to line currents flowing in linear wires placed above the film, and we present analytic expressions for the magnetic-field and current distributions based on the critical…
High critical current density Jc is generally the most important property of any superconductor used for applications. The critical current Ic is most frequently measured by transport 4 probe V-I techniques and the measured Ic is then…
Magneto-optical current reconstruction has been used for detailed analysis of the local critical current density (Jc) variation in monocore Bi-2223 tapes. We find, even in high quality tapes with bulk transport Jc ~ 40 kA/cm^2 (77K, 0T),…
Optimally doped single crystals of Ba(Fe$_{1-x}$T$_x$)$_2$As$_2$ (T=Co, Ni) were irradiated with 1.4 GeV $^{208}$Pb$^{56+}$ ions at fluences corresponding to matching fields of $B_{\phi}=0.1, 0.5, 1$ and 2 T. Magneto-optical imaging has…
High quality bulk MgB2 exhibit a structure of voids and agglomeration of crystals on different length-scales. Because of this, the superconducting currents percolate between the voids in the ensuing structure. Magnetic measurements reveal…
Various local probes have been applied to understanding current flow through superconducting films, which are often surprisingly inhomogeneous. Here we show that magnetic imaging allows quantitative reconstruction of both current density,…
If the critical current density Jc is very high for a superconductor, then estimating its value from transport measurements is not very easy. In such cases, the value of Jc, called Jcm for magnetic Jc, is usually obtained from the measured…
We investigate the in-field critical current density Jc(B) of SNS Josephson Junctions (JJs) and polycrystalline superconductors with grain boundaries modelled as Josephson type planar defects, both analytically and through computational…
The critical current density of a superconducting film can be easily determined by an inductive and contactless method. Driving a sinusoidal current in a single coil placed in front of a superconducting sample, a non zero third harmonic…
In order to understand why the inter- and intra-granular current densities of polycrystalline superconducting oxypnictides differ by three orders of magnitude, we have conducted combined magneto-optical and microstructural examinations of…
Magnetization hysteresis loops and the ac susceptibility of a superconducting thin disk are calculated in the critical-state model assuming a field-dependent critical current density, Jc(B). The results are obtained by solving numerically…