Related papers: Peak effect in single crystal MgB$_2$ superconduct…
Time resolved magneto-optical images show hysteresis associated with the transition at the so-called ``second magnetization peak'' at B_sp in single-crystalline Bi_2Sr_2CaCu_2O_8+d. By rapid quenching of the high-field phase, it can be made…
We analyse the phase transition between the Bragg Glass and the Disordered phase in the vortex lattice in type-II superconductors, both by analytical computations and experimental investigations. It is known that if the Peak Effect can be…
The peak effect in weakly pinned superconductors is accompanied by metastable vortex states. Each metastable vortex configuration is characterized by a different critical current density J_c, which mainly depends on the past thermomagnetic…
We review recent measurements of upper (Hc2) and lower (Hc1) critical fields in clean single crystals of MgB2, and their anisotropies between the two principal crystallographic directions. Such crystals are far into the "clean limit" of…
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…
We report the results of an experimental study of dc and low frequencies magnetic properties of K$_{0.8}$Fe$_{2}$Se$_2$ single crystal when the dc magnetic field is applied parallel to the $\bf{ab}$ plane. From the data obtained, we deduce…
The angular and temperature dependence of the upper critical field Hc2 in MgB2 was determined from torque magnetometry measurements on single crystals. The Hc2 anisotropy gamma_H was found to decrease with increasing temperature, in…
Using small-angle neutron scattering we have studied the vortex lattice in superconducting MgB$_2$ with the magnetic field applied along the $c$-axis, doped with either manganese or carbon to achieve a similar suppression of the critical…
We present here some newer characteristics pertaining to paramagnetic Meissner effect like response in a single crystal of the low Tc superconducting compound 2H-NbSe2 via a detailed study of effects of perturbation on the field-cooled…
A comparative study of magnetic behavior in a DC magnetic field up to 19 Tesla has been undertaken on different Nb3Sn samples, i.e. single crystals, polycrystal samples and multifilamentary wires. From the 1st and 3rd harmonics of the AC…
We present measurements of the superconducting upper critical field Hc2(T) and the magnetic phase diagram of the superconductor ErNi2B2C made with a scanning tunneling microscope (STM). The magnetic field was applied in the basal plane of…
We present the results of directional point-contact spectroscopy in state-of-the-art Mg_{1-x}Al_xB_2 and Mg(B_{1-y}C_{y})_2 single crystals produced at ETH, Zurich. Fitting the conductance curves of our point contacts, that always feature…
The screening response of vortices in kagome superconductor CsV$_3$Sb$_5$ was measured using the ac mutual inductance technique. Besides confirming the absence of gapless quasiparticles in zero external magnetic field, we observe the peak…
Magnetization and its relaxation have been measured in $Ba(Fe_{1-x}Co_x)_2As_2$ single crystals at various doping levels ranging fromvery underdoped to very overdoped regimes. Sizable magnetization relaxation rate has been observed in all…
We report additional experimental evidences about the presence of an universal behavior in the Field-Temperature Phase Diagram of Type II Superconductors. This behavior is characterized by a phase transition in the vortex matter between the…
By means of local Hall probe ac and dc permeability measurements we investigated the phase diagram of vortex matter for the HgBa$_2$CuO$_{4+\delta }$ superconductor in the regime near the critical temperature. The second peak line, $H_{\rm…
The results of the first directional point-contact measurements in MgB2 single crystals, in the presence of magnetic fields up to 9 T either parallel or perpendicular to the ab planes, are presented. By applying suitable magnetic fields, we…
We report on study of the electronic anisotropy of the newly discovered MgB2 superconductor using the in-plane resistivity measurements in magnetic field applied perpendicular and parallel to Mg and B planes of MgB2 single crystals. The…
In the mixed state of type II superconductors, vortices penetrate the sample and form a correlated system due to the screening of supercurrents around them. Interestingly, we can study this correlated system as a function of density and…
We report high magnetic field linear magnetostriction experiments on CeCoIn$_5$ single crystals. Two features are remarkable: (i) a sharp discontinuity in all the crystallographic axes associated with the upper superconducting critical…