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We report the properties of superconductivity and Hall effect in 100 nm Pb 8 2 Bi 1 8 alloy thin films which were prepared by thermal evaporation with quench condensation using liquid nitrogen. X-ray diffraction indicates the films are α -phase with peaks shifted to lower angles compared to pure Pb. The T C of the films was higher than those of an amorphous Pb–Bi alloy thin film of the same composition and pure bulk Pb. The resistivity, critical field and critical current density of the thin films are reported. The coherence length (ξ ) and London penetration depth (λ) near T C were calculated from the experimental results. The films are in the dirty limit and behave as type-II superconductors with a Ginzburg–Landau parameter of about 10. Additionally, the films show sign reversal in Hall measurements. These films have been quite useful in a comprehensive study of the effects of flux pinning by integrated ferromagnetic nanostructures conducted in hybrid ferromagnet–superconductor samples in our lab over the past few years due to their single-phase nature and strong type-II behavior. [ABSTRACT FROM AUTHOR]

Studies of the transport properties of a superconducting film with several (1-7) parallel nickel magnetic nanostripes deposited on the top of a thin insulating layer covering the surface of the superconducting film are reported. Measurements of the dependence of the resistance on the in-plane magnetic field with two magnetic field orientations (parallel to the stripes direction and perpendicular to the stripes) and the temperature have been made. We have studied resistance versus in-plane magnetic field direction. Different types of strong hysteresis in the resistance dependence on the magnetic field for different magnetic field orientations were observed. [ABSTRACT FROM AUTHOR]

After the 100th year anniversary of the discovery of superconductivity, the field continues to develop in several directions; including ferromagnet-superconductor hybrids.1-5 Magnetic and superconducting states are perhaps the most extreme example of mutually exclusive states. However, when combined at the nanoscale, they show new exciting properties and enhanced superconductivity. Here we report the measurements and simulation of the phase diagram of a thin superconducting film with an array of magnetic nanorods (MNR) embedded in the film. Results of the experimental measurements of the phase diagram of a PbBi superconducting film with embedded arrays of nanorods are reported and compared with the simulated phase diagrams. [ABSTRACT FROM AUTHOR]

By using micron size permanent magnets we have trapped directly single diamagnetic micron size polystyrene microspheres inside a buffer solution with a magnetic field and demonstrated self-assembly of several hundred microns long chains of microspheres in magnetic traps. [ABSTRACT FROM AUTHOR]

The effects of crystal lattice disorder induced by irradiation of La-Ca-Mn-O films are reviewed. These experiments provide insight into the anomalous transport properties and colossal magnetoresistance (CMR) of these perovskites. Electron irradiation produces only slight lattice damage, about 10[sup -5] displacements per atom (dpa) which would be imperceptible in an ordinary "bad "metal or activated semiconductor but gives large changes in resistance that illustrate the exotic nature of transport in both the metallic and insulating phases of the CMR films. Ion irradiation produces damage ranging from 5 × 10[sup -3] dpa to 2.4 × 10[sup -2] dpa which provides a systematic picture of CMR and transport from relatively small lattice disorder to more severe disorder, sufficient to completely supress the metal-insulator (M-I) transition. [ABSTRACT FROM AUTHOR]

YbNi[sub 2]B[sub 2]C has been found to be a heavy fermion metal with neither superconductivity nor magnetic order in contrast to the other members of the borocarbide family. LuNi[sub 2]B[sub 2] C is a superconductor with T[sub c] ∼ 16.3K and no magnetic order. Transport studies on single crystal Yb[sub χ] Lu[sub (l - χ)]Ni[sub 2]B[sub 2]C show a systematic change from a heavy fermion system to a moderately high-temperature superconductor. A "giant" thermopower is observed for small × to × = l, i.e., in the transition region from a Kondo alloy to a heavy fermion metal. Measurements of H[sub c2] (T,x) are also reported for x<0.15. [ABSTRACT FROM AUTHOR]

The in-plane resistance of single crystal non-magnetic Lu[sub x]Y[sub 1-x]Ni[sub 2]B[sub 2]C and magnetic Lu[sub x]Gd[sub 1-x]Ni[sub 2]B[sub 2]C samples as a function of the magnitude and direction of the magnetic field and temperature have been measured. The superconducting upper critical field H[sub c2](T) is anisotropic for both. A positive curvature in H[sub c2](T) near T[sub c](x) is clearly observed only for the non-magnetic impurity. At low temperature H[sub c2](T) for the sample with magnetic impurities is strongly reduced. Thermopower, thermal conductivity and resistivity as a function of temperature are also reported for Lu[sub x]Gd[sub 1-x]Ni[sub 2]B[sub 2]C. [ABSTRACT FROM AUTHOR]

In-plane resistance as a function of magnitude and direction of the magnetic field and the temperature has been measured for TmNi[sub 2]B[sub 2]C from above the superconducting transition temperature at 10.7 K to below the magnetic transition TN=1.5 K. The superconducting upper critical field H[sub C2](T) exhibits a large anisotropy and structure in the vicinity of T[sub N]. The magnetoresistance above T[sub C] is large and changes sign as the direction of the magnetic field is rotated from in-plane to parallel with the c-axis. [ABSTRACT FROM AUTHOR]