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We characterize thermally quench condensed (~80 K) Sn thin films of two different thicknesses to explore their usefulness for vortex studies. The coherence length and the London penetration depth near the critical temperature indicate that the thin films are in the dirty limit and behave as type II superconductors. Furthermore, when we add ferromagnetic nanostripes on top of the Sn thin films, the ferromagnet-superconductor hybrids show hysteric and anisotropic behavior. A ferromagnet-superconductor hybrid with a thinner Sn film exhibits a stronger effect.

We report the properties of superconductivity and Hall effect in 100 nm Pb[Formula: see text]Bi[Formula: see text] alloy thin films which were prepared by thermal evaporation with quench condensation using liquid nitrogen. X-ray diffraction indicates the films are [Formula: see text]-phase with peaks shifted to lower angles compared to pure Pb. The [Formula: see text] 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 ([Formula: see text][Formula: see text]) and London penetration depth ([Formula: see text]) near [Formula: see text] 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.

The thermal diffusivity of YBa2Cu3O7−x (YBCO) film was measured using the optical pump–probe method. A theoretical finite-difference model was employed to calculate the diffusivity value, and the best fit for the c-axis oriented YBCO film showed an average thermal diffusivity of 0.25 ± 0.05 mm2 s−1. The obtained result is compared to previous reports measured using various methods.

We discuss the transport properties of a superconducting film under the influence of a tesla range spatially alternating magnetic field created by magnetic nanostructures placed outside a superconducting film with an insulating barrier between both so that they interact only via the magnetic field. A simple model for pinning by the spatially periodic magnetic field from the magnetic nanostructure qualitatively describes the data.

In Magnet/Superconductor Nanostructures it is possible to control magnetism and conductivity at the nanoscale by using localized magnetic fields from structural (dots, stripes, wires) and topological (vortices's, skyrmions and domain walls) textures in magnet and/or superconductor subsystems of the hybrid material. We review experimental and theoretical results in the field of nanostructured magnet/superconductor systems.

The quaternary intermetallic rare-earth nickel borocarbides, RNi 2 B 2 C, are a family of compounds that show magnetic behavior, superconducting behavior, and/or both. Thermal transport measurements reveal both electron and phonon scattering mechanisms, and can provide information on the interplay of these two long-range phenomena. For R=Dy and Ho, the thermal conductivity is dominated by electrons and the low temperature thermal conductivity exhibits a marked loss of scattering at the antiferromagnetic ordering temperature, T N . Unlike the case for R=Y and Lu non-magnetic superconductors, a phonon peak in the thermal conductivity below T c is not observed down to T =1.4 K for the R=Dy and Ho magnetic superconductors.

We have fabricated two-dimensional periodic arrays of parallel magnetic and superconducting nanowires on a silicon substrate. Parallel magnetic (nickel) nanowires of cross section 90 nm by 300 nm form a periodic array with Pb82Bi18 superconducting nanowires of cross section 200 nm by 100 nm. These nanostructures were characterized with Scanning Electron Microscopy (SEM) and magnetic properties were studied with Magnetic Force Microscopy (MFM). The phase diagram was determined by electrical transport measurements. Depending on the temperature, the second critical field was 2 to 3 times larger than that of a homogeneous Pb82Bi18 superconducting control film. The superconducting phase diagram and transport properties exhibit strong hysteresis in a magnetic field. Results are explained on the basis of the theory of magnet–superconductor hybrids.

Superconducting properties of a new ferro-magnet–superconductor hybrid structure have been investigated. Organized arrays of Co nanowires are first electroplated into the columnar pores of anodic aluminum oxide (AAO) membranes. Superconducting Pb/Bi (18 at.%) films are then quench-condensed onto the surface of the AAO membranes filled with Co nanowires. The Co nanowire array produces a magnetic field with a strong spatial variation in the superconducting film. Hysteretic superconducting properties and enhanced critical currents have been observed in applied external magnetic fields, which we explain based on the magnetic domain structure of the Co nanowire arrays.

We propose a new class of composite superconductors with embedded magnetic nanoparticles/nanorods. These nanomagnets can create a thermodynamically stable, frozen, dense flux line network. We discuss the methods of fabrication of these novel materials. We show that due to the frozen flux created by magnetic nanorods, the critical current in this composite superconductor can be higher than in the superconductor with a comparable density of columnar defects.

The in-plane resistivity, in-plane absolute thermopower, and upper critical field measurements are reported for single-crystal samples of ${\mathrm{YNi}}_{2}$${\mathrm{B}}_{2}$C and ${\mathrm{LuNi}}_{2}$${\mathrm{B}}_{2}$C superconductors. The in-plane resistivity shows metallic behavior and varies approximately linearly with temperature near room temperature (RT) but shows nearly quadratic behavior in temperature at low temperatures. The ${\mathrm{YNi}}_{2}$${\mathrm{B}}_{2}$C and ${\mathrm{LuNi}}_{2}$${\mathrm{B}}_{2}$C single-crystal samples exhibit large transverse magnetoresistance (\ensuremath{\approx}6--8 % at 45 kOe) in the ab plane. The absolute thermopower S(T) is negative from RT to the superconducting transition temperature ${\mathrm{T}}_{\mathrm{c}}$. Its magnitude at RT is a few times of the value for a typical good metal. S(T) is approximately linear in temperature between \ensuremath{\approx}150 K and RT. Extrapolation to T=0 gives large intercepts (few \ensuremath{\mu}V/K) for both samples suggesting the presence of a much larger 'knee' than would be expected from electron-phonon interaction renormalization effects. The upper critical fields for H parallel and perpendicular to the c axis and the superconducting parameters derived from it do not show any anisotropy for the ${\mathrm{YNi}}_{2}$${\mathrm{B}}_{2}$C single-crystal samples in agreement with magnetization and torque magnetometry measurements, but a small anisotropy is observed for the ${\mathrm{LuNi}}_{2}$${\mathrm{B}}_{2}$C single crystals. The analysis shows that these are moderately strong-coupling type-II superconductors (similar to the A-15 compounds) with a value of the electron-phonon coupling parameter \ensuremath{\lambda}(0) approximately equal to 1.2 for ${\mathrm{YNi}}_{2}$${\mathrm{B}}_{2}$C and 1.0 for ${\mathrm{LuNi}}_{2}$${\mathrm{B}}_{2}$C, the Ginzburg-Landau coherence length \ensuremath{\xi}(0) approximately equal to 70 \AA{}, and ${\mathrm{H}}_{\mathrm{c}2}$(0)\ensuremath{\sim}60--70 kOe. The temperature dependence of the upper critical field shows a positive curvature near ${\mathrm{T}}_{\mathrm{c}}$ in disagreement with the Werthamer, Helfand, Hohenberg, and Maki (WHHM) theory but in agreement with a recent solution of the Gor'kov equation using a basis formed by Landau levels (Bahcall); however, the data show a severe disagreement between the observed low-temperature behavior of ${\mathrm{H}}_{\mathrm{c}2}$(T) and that predicted either by WHHM or Bahcall's expressions.

RNi2B2C (R=Y, Lu−Gd) intermetallics show diverse behavior, including moderately high temperature superconductivity (R=Y, Lu), coexistence of superconductivity with magnetic order (R=Tm−Dy), only magnetic order (R=Tb, Gd), and heavy fermion behavior without superconductivity or magnetic order (R=Yb). The large energy scale of the crystal electric field splitting of lanthanide orbitals leads to large anisotropies in the magnetic and superconducting properties of many of these compounds. Single crystal transport measurements can help determine the influence of anisotropy on magnetic and superconducting phase boundaries as illustrated by the phase diagram for HoNi2B2C determined by transport and magnetic measurements and delineate the important scattering mechanisms by resistivity and thermopower measurements across the series.

The in-plane resistivity and magnetization measurements as a function of the magnitude and direction of the magnetic field and the temperature are reported for single-crystal samples of the HoNi{sub 2}B{sub 2}C magnetic superconductor. Features corresponding to several distinct magnetic phases and the coexistence of superconductivity with two of the magnetic phases are observed. Contrary to previous measurements for polycrystalline samples, reentrant superconductivity is not observed in the absence of a field for these samples. The measurements indicate an extremely rich interplay between superconductivity and different magnetic structures that can be influenced by field, temperature, and current. The results correlate quantitatively with and complement previous determinations of the magnetic phase diagram and qualitatively with determinations of the superconducting phases by measurements of the single-crystal magnetization and heat capacity. HoNi{sub 2}B{sub 2}C is highly anisotropic, and phase diagrams for the field along the (100) and (001) directions are presented. {copyright} {ital 1996 The American Physical Society.}

Granular superconductivity effects in a polycrystalline sample of ruthenocuprate RuSr$_2$(Gd$_{1.5}$Ce$_{0.5})$Cu$_2$O$_{10-\delta}$ are studied. The main attention has been devoted to manifestation of these effects in current and magnetic-field dependences of resistive transition to superconducting state. It is found that current dependences of differential resistance taken at different temperatures intersect strictly at two definite values of current demonstrating crossing point effect. This phenomenon has been explained taking into account inhomogeneous state of intergrain medium which can be considered as a two-component system. The particular attention has been given to magnetoresistance (MR) hysteresis in mixed state of this inhomogeneous system and to influence of applied current and temperature on this phenomenon. Two types of hysteresis (clockwise and anticlockwise) have been found with transition from clockwise to anticlockwise hysteresis with increasing temperature. Stepwise structure in MR hysteretic curves has been observed in low-field range. Possible reasons of the change in hysteresis behavior with increasing temperature and appearance of the stepwise structure in MR curves are discussed taking into consideration inhomogeneous state of the granular superconductor studied., Comment: 31 pages, 13 figures

The point-contact (PC) spectra of the Andreev reflection dV/dI curves of the superconducting rare-earth nickel borocarbide ErNi2B2C (Tc=11 K) have been analyzed in the "one-gap" and "two-gap" approximations using the generalized Blonder-Tinkham-Klapwijk (GBTK) model and the Beloborod'ko (BB) model allowing for the pair-breaking effect of magnetic impurities. Experimental and calculated curves have been compared not only in shape, but in magnitude as well, which provide more reliable data for determining the temperature dependence of the energy gap (or superconducting order parameter) \Delta(T). The anisotropic effect of antiferromagnetic ordering at T_N =6 K on the superconducting gap/order parameter has been determined: as the temperature is lowered, \Delta(T) decreases by 25% in the c-direction and only by 4% in the ab-plane. It is found that the pair-breaking parameter increases in the vicinity of the magnetic transitions, the increase being more pronounced in the c-direction. The efficiency of the models was tested for providing \Delta(T) data for ErNi2B2C from Andreev reflection spectra., Comment: 16 two column pages, 20 figs., will be published in Fiz. Nizk. Temp. N10, 2010; V2: added - "Acknowledgement" & "Note added in proof"

Point contacts (PC) Andreev reflection dV/dI spectra for the antiferromagnetic (T_N =6K) superconductor (Tc=11K) ErNi2B2C have been measured for the two main crystallographic directions. Observed retention of the Andreev reflection minima in dV/dI up to Tc directly points to unusual superconducting order parameter (OP) vanishing at Tc. Temperature dependence of OP was obtained from dV/dI using recent theory of Andreev reflection including pair-breaking effect. For the first time existence of a two superconducting OPs in ErNi2B2C is shown. A distinct decrease of both OPs as temperature is lowered below T_N is observed., 5 pages, 5 figs, to be published in Europhys. Lett

Enhancements of the low-temperature thermopower of amorphous melt-quenched (Zr0.64Ni0.36)1-xAlx alloys with x=0, 0.05 , 0.10, 0.15, 0.20 and 0.25 are shown to be in good agreement with the predictions for the electron-phonon enhancement. The results imply that the low-frequency part of the Eliashberg function alpha 2( omega ) F( omega ) is proportional to omega n with n>1 for these alloys. These alloys are weak-coupling superconductors, and the addition of Al reduces the electron-phonon coupling constant lambda despite the tendency to strong coupling in simple amorphous metals.

We have fabricated a new type of magnet-superconductor hybrid (MSH): an ordered array of magnetic nanorods atop a superconducting film electrically insulated from the array. Transport properties of this MSH, [Formula: see text] and [Formula: see text] are reported. We compare these results with those for a superconducting film atop an alumina template with an array of magnetic nanowires.

We present results on electrochemical fabrication of arrays of magnetic nanostripes atop a Sn film covered with an insulating Ge layer. We also report its transport properties and superconducting [Formula: see text]. The transport properties demonstrate strong hysteresis as a function of the magnetic field.

An overview of the recent efforts in point-contact (PC) spectroscopy of the nickel borocarbide superconductors RNi2B2C in the normal and superconducting (SC) state is given. The results of measurements of the PC electron- boson(phonon) interaction spectral function are presented. Phonon maxima and crystalline-electric-field (CEF) excitations are observed in the PC spectra of compounds with R=Dy, Ho, Er and Tm, while for R=Y a dominant phonon maximum around 12 meV is characteristic. Additionally, non-phonon and non-CEF maxima are observed near 3 meV in R=Ho and near 6 meV in R=Dy. Directional PC study of the SC gap gives evidence for the multi-band nature of superconductivity in R=Y, Lu. At low temperature the SC gap in R=Ho exhibits a standard single-band BCS-like dependence, which vanishes above T_c^*= 5.6K< T_c=8.5K, where a specifc magnetic ordering starts to play a role. For R=Tm (T_c=10.5 K) a decrease of the SC gap is observed below 5 K., 7 figs, 4 pages, presented on M2S-HTSC Conference, July 9-14, 2006, Dresden

It is shown that the two-gap approximation is applicable for describing the $dV/dI(V)$ spectra of LuNi$_{2}$B$_{2}$C-Ag point contacts in a wide interval of temperatures. The values and the temperature dependences of the large and the small gaps in the $ab$ plane and in the $c$ direction were estimated using the generalized BTK model and the equations of Beloborodko. In the BCS extrapolation the critical temperature of the small gap is 10 $K$ in the $ab$ plane and 14.5 $K$ in the $c$ direction. The absolute values of the gaps are $\Delta_0^{ab}=2.16$ $meV$ and $\Delta_0^c=1.94$ $meV$. For the large gaps the critical temperature coincides with the bulk $T_c$, $T_c^{bulk}=16.8$ $K$, and their absolute values are very close, being about 3 $meV$ in both orientations. In the $c$ direction the contributions to the conductivity from the small and the large gaps remain practically identical up to $10 \div 11$ $K$. In the $ab$ plane the contribution from the small gap is much smaller and decreases rapidly as a temperature rises., Comment: 10 pages, 10 figures, submitted to Fiz. Nizk. Temp. (Low Temp. Phys.)

Measurements of in-plane resistivivity and thermopower for single crystal Y(Ho, Tm)Ni2B2C magnetic superconductors show a metallic resistivity and negative thermopower.

The quaternary intermetallic rare-earth nickel borocarbides $R{\mathrm{Ni}}_{2}{\mathrm{B}}_{2}\mathrm{C}$ are a family of compounds that show magnetic behavior, superconducting behavior, and/or both. Thermal transport measurements reveal both electron and phonon scattering mechanisms, and can provide information on the interplay of these two long-range phenomena. In general the thermal conductivity $\ensuremath{\kappa}$ is dominated by electrons, and the high temperature thermal conductivity is approximately linear in temperature and anomalous. For $R=\mathrm{Tm},$ Ho, and Dy the low-temperature thermal conductivity exhibits a marked loss of scattering at the antiferromagnetic ordering temperature ${T}_{N}.$ Magnon heat conduction is suggested for $R=\mathrm{Tm}.$ The $\ensuremath{\kappa}$ data for $R=\mathrm{Ho}$ lends evidence for gapless superconductivity in this material above ${T}_{N}.$ Unlike the case for the non-magnetic superconductors in the family, $R=\mathrm{Y}$ and Lu, a phonon peak in the thermal conductivity below ${T}_{c}$ is not observed down to $T=1.4\mathrm{K}$ for the magnetic superconductors. Single-crystal quality seems to have a strong effect on $\ensuremath{\kappa}.$ The electron-phonon interaction appears to weaken as one progresses from $R=\mathrm{Lu}$ to $R=\mathrm{Gd}.$ The resistivity data shows the loss of scattering at ${T}_{N}$ for $R=\mathrm{Dy},$ Tb, and Gd; and the thermoelectric power for all three of these materials exhibits an enhancement below ${T}_{N}.$

Novel low dimensional quantum phenomena at (110) LaAlO3/SrTiO3 (LAO/STO) interfaces are expected after the quasi two dimensional electron gas similar to that of (001) LAO/STO interfaces was found at this (110) system. Here, we report the two dimensional superconductivity with a superconducting transition temperature of ≅ 184 mK at (110) LAO/STO interfaces. The two dimensional characteristics of the superconductivity are consistent with our analysis based on a Berezinskii-Kosterlitz-Thouless transition. The estimated superconducting layer thickness is about 18 nm. This discovery may inspire new studies of LAO/STO interfaces and open additional opportunities for design of novel oxide electronic devices.

We discuss a new class of phenomena based on strong interaction between magnetic flux from magnetic textures and supercurrents in emerging mesoscopic, heterogeneous magneto-superconducting systems. These systems include coupled smooth and textured magnetic/superconducting films, magnetic dots, columns, stripes embedded in super-conducting material, etc. The frozen magnetic flux from magnetic textures or topological defects can pin vortices or create them, changing drastically the properties of the superconductor. On the other hand, the magnetic field from supercurrents (vortices) strongly interacts with the magnetic subsystem. This results in spontaneous ground state supercurrents and in formation of coupled magnetic-superconducting topological defects. We discuss possible experimental realization of mesoscopic magneto-superconducting systems.

We present studies of the transport properties of a Sn superconducting film with an array of parallel nickel magnetic nanostripes (800 nm period) deposited on top of a germanium insulating layer covering the Sn film surface. The critical current parallel to the stripes is larger than the critical current perpendicular to the stripes. Both critical currents demonstrate strong hysteresis and matching field effects. We have observed strong hysteresis in the resistance dependence on the magnetic field.

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 Ni nanorods are reported and compared with the simulated phase diagrams.

Studies of the transport properties of a Sn superconducting film with several (1–7) parallel nickel magnetic nanostripes deposited on the top of a thin Ge 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.

The superconducting properties of Pb82Bi18 alloy films deposited on ferromagnetic nanowire arrays have been investigated. Ferromagnetic Co or Ni nanowires are first electroplated into the columnar pores of anodic aluminum oxide (AAO) membranes. Superconducting Pb82Bi18 films are then quench condensed onto the polished surface of the AAO membranes filled with magnetic nanowires. A strong dependence of the Pb82Bi18 superconducting properties on the ratio of the superconducting film thickness to the magnetic nanowire diameter and material variety was observed.

We report measurements of the magnetoresistance and phase diagram of a PbBi superconducting film with an embedded square array of Ni nanorods near the superconducting transition temperature. A magnetoresistance above Tc demonstrates oscillations compatible with flux quantization through the unit cell of the magnetic nanorod array. Strong hysteresis of the superconducting properties and an apparent increase of the second critical field are found.

We report measurements of the phase diagram and critical current of a PbBi superconducting film with an embedded square array of Ni nanorods. Strong hysteresis of the superconducting properties and an increase in the critical current which varies from several times to several orders of magnitude depending on the magnetic field and temperature is found.

We consider a new class of composite superconducting films with embedded magnetic nanorods (stripes). These nanomagnets can create a thermodynamically stable, frozen, dense flux line network. We examine conditions under which the magnetic nanorods (stripes) capture flux and discuss the phase diagram of the frozen flux state. The ground state of this system contains spontaneous current in violation with the time-reversal symmetry.

The Neel temperature (TN) of the magnetic superconductor HoNi2B2C is below its superconducting transition temperature [1] (Tc) while DyNi2B2C becomes superconducting below the magnetic ordering temperature [2] (Tc

This letter reports on a microfabricated magnet-superconducting hybrid structure (Co–SiO2–Pb82Bi18) showing the dependence of the critical current (Ic) on the current flow direction. With external magnetic field, intermittent superconducting and normally conducting regions are formed on the Pb82Bi18 film due to field localization created by the Co stripes, which is verified by scanning Hall probe microscopy measurements. Superconducting and normal conduction paths are created parallel and perpendicular to the Co stripes, providing directional dependency on the current flow. By changing the orientation of the ferromagnetic stripes with respect to the superconducting film, the hybrid structure could be adapted to realize a low-power persistent current switch.

Superconducting properties of 60 nm thick lead bismuth (Pb82Bi18) films in a spatially varying magnetic field created by a hybrid structure of soft magnetic (25 μm wide iron) and nonmagnetic (250 μm wide brass) layers perpendicular to the superconducting film surface are reported. The applied homogeneous external magnetic field is redistributed in the superconducting film due to the high magnetic permeability of iron. This results in alternating parallel stripes of regions of low and high magnetic field. Thus the values of second critical field HC2 and critical current density are also much higher for current parallel to the magnetic stripes than in a control superconducting film without any magnetic field modulation. For the current perpendicular to the magnetic stripes, the superconductor behaves like an inhomogeneous resistor with regions of low and higher TC in series. Thus, the critical current IC for the perpendicular case is much less than either the control film or the case for current parallel to...

Granular superconductivity effects in polycrystalline samples of RuSr2(Gd1.5Ce0.5)Cu2O10??, as prepared (by a solid-state reaction method) and annealed (12?h at 845??C) in pure oxygen at 30?atm, are presented. The resistive transition to the superconducting state of the as-prepared sample is found to be considerably affected by granularity. In particular, an evident kink in the temperature dependence of the resistance R(T) is seen at the temperature, Tc0?34?K, at which grains become superconducting. The resistive transition depends strongly on the applied current. The family of R(T) curves taken for different transport currents is branched with a branching point at TcJ?23.2?K. Below this temperature the intergrain Josephson coupling starts to develop. For low current, R decreases with decreasing temperature below TcJ as expected for the transition to the superconducting state, whereas R(T) curves for higher current form a minimum at T?17.3?K, showing a quasi-re-entrant behaviour. The influence of the granular structure of the as-prepared sample shows itself also in the temperature behaviour of the magnetization, M(T), in low field. Application of low magnetic field (below 400?Oe) leads to a broadening of the resistive transitions below TcJ, similar to that caused by increasing the current. Both the current and magnetic field depress the Josephson coupling between the grains, producing a dramatically large effect on the resistive transition. The R(T) and M(T) dependences of the annealed sample show a fairly sharp superconducting transition far less affected by granularity. The results obtained imply that oxygen annealing improves the intergranular connection considerably, but it does not exert much influence on the intragrain superconductivity. No indication of intragrain granularity has been found in the samples studied. The influence of ageing (due to deoxidation) of samples for different conditions of storage is considered briefly as well.

The metamagnetic transitions in single-crystal rare-earth nickel borocarbide HoNi_{2}B_{2}C and ErNi_{2}B_{2}C have been studied at 1.9 K with a Quantum Design torque magnetometer. The critical fields of the transitions depend crucially on the angle between applied field and the easy axis [110] for HoNi_2B_2C and [100] for ErNi_2B_2C. Torque measurements have been made while changing angular direction of the magnetic field (parallel to basal tetragonal ab-planes) in a wide angular range (more than two quadrants). The results are used not only to check and refine the angular diagram for metamagnetic transitions in these compounnds, but also to find new features of the metamagnetic states. Among new results for the Ho borocarbide are the influence of a multidomain antiferromagnetic state, and ``frustrated'' behavior of the magnetic system for field directions close to the hard axis [100]. Torque measurements of the Er borocarbide clearly show that the sequence of metamagnetic transitions with increasing field (and the corresponding number of metamagnetic states) depends on the angular direction of the magnetic field relative to the easy axis., Comment: 3pages (4 figs. incl.) reported at 50th Magnetism and Magnetic Materials Conference, San Jose, CA, USA, 2005

Resistance vs temperature,R(T), curves for ultra-thin homogeneous Mo-Ru films are analyzed using recent theories for the temperature dependence of the resistance in the insulating phase, and the suppression of the superconducting transition temperature,T c , with increasing normal state sheet resistance,R [], in the superconducting phase.