Related papers: Peak effect in single crystal MgB$_2$ superconduct…
We synthesized hexagonal-disc-shaped MgB2 single crystals under high-pressure conditions and analyzed the microstructure and pinning properties. The lattice constants and the Laue pattern of the crystals from X-ray micro-diffraction showed…
Strongly disordered superconductors in a magnetic field display many characteristic properties of type-II superconductivity--- except at low temperatures where an anomalous linear $T$-dependence of the resistive critical field $B_{c2}$ is…
A superconducting transition in the temperature dependence of the ab-plane resistivity of underdoped YBa_2Cu_3O_{6+x} crystals in the range T_c<30 K has been investigated. Unlike the case of samples with the optimal level of doping, the…
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 measure the ac susceptibility of single-crystal CeCoIn5 in dc field parallel to the c axis and find further evidence for a high-field phase transition within the superconducting phase in this orientation. We apply up to 2.3 kbar uniaxial…
The recently discovered superconductivity in MgB2 has captured world attention due to its simple crystal structure and relatively high superconducting transition temperature Tc=39K. It appears to be generally accepted that it is…
We report measurements of the magnetic penetration depth \lambda_m(T) in the presence of a DC magnetic field in optimally doped BSCCO-2212 single crystals. Warming, after magnetic field is applied to a zero-field cooled sample, results in a…
It is shown that the transition to the low temperature superconducting state in a 3D metal at high magnetic field is smeared dramatically by thermal fluctuation of the superconducting order parameter. The resulting superconducting-to-normal…
Measurements of the superconducting upper critical field, H_{c2}, and critical current density, J_c, have been carried out for MgB_2 doped with Ti and/or C in order to explore the problems encountered if these dopants are used to enhance…
In magnetic measurements on Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi-2212) single crystals, a general peak with a dynamical feature on both $S-H$ and $S-T$ curves was found with S the magnetic relaxation rate. At higher fields, the…
We present thermal expansion and magnetostriction measurements on a CeCu2Si2 single crystal of A/S-type up to 17.9T magnetic field applied along the crystallographic a-direction (Delta L ll a ll H) and down to 0.015K temperature. We…
The peak effect (PE) has been observed in a twinned crystal of YBa$_2$Cu$_3$O$_{7-\delta}$ for H$\parallel$c in the low field range, close to the zero field superconducting transition temperature (T$_c$(0)) . A sharp depinning transition…
The magnetic response related to paramagnetic Meissner effect (PME) is studied in a high quality single crystal ZrB12 with non-monotonic vortex-vortex interactions. We observe the expulsion and penetration of magnetic flux in the form of…
From magnetisation measurements we provide evidence that the ferromagnetic superconductor RuSr$_{2}$GdCu$_{2}$O$_{8}$ with \QTR{it}{T}$_{c}$=45 K and \QTR{it}{T}$_{M}$=137 K exhibits a sizeable diamagnetic signal at low temperature…
We investigated vortex dynamics in a single-crystal sample of type-II superconductor NbSe$_{2}$ using scanning tunneling microscopy at 4.2 K. The decay of the magnetic field at a few nT/s in our superconducting magnet induced the…
The phenomenon of superconductivity was discovered in 1911, however, the methodology to classify and distinguish type-II superconductivity was established only in late fifties after Abrikosov's prediction of a flux line lattice in 1957. The…
Fine grained polycrystalline samples of MgB(2) superconductor were synthesized from the elements to contain < 5 % of impurity phases, according to X-ray powder diffractometry. The superconductive transition was sharp with a midpoint Tc =…
Specific heat, dc- and ac-magnetic susceptibility are reported for a large single crystal of PrOs$_4$Sb$_{12}$ and, after grinding, its powder. The room temperature effective paramagnetic moment of the crystal was consistent with the…
We have measured small-amplitude rf penetration depth $\lambda(H,T)$ in pure and C, Li and (Li+C) doped single crystals of MgB$_2$. The effect of doping on the critical temperature T$_c$ and on the upper critical field H$_{c2}$ was found to…
Precision measurements of the vortex phase diagram in single crystals of the layered superconductor Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ in oblique magnetic fields confirm the existence of a second phase transition, in addition to the…