Electronic reconstruction and enhanced superconductivity at La1.6−x_{1.6-x}Nd0.4_{0.4}Srx_{x}CuO4_{4}/La1.55_{1.55}Sr0.45_{0.45}CuO4_{4} bilayer interface

We report enhanced superconductivity in bilayer thin films consisting of superconducting La$_{1.6-x}$Nd$_{0.4}$Sr$_{x}$CuO$_{4}$ with 0.06 $\leq x<$ 0.20 and metallic but non-superconducting La$_{1.55}$Sr$_{0.45}$CuO$_{4}$. These bilayers show a maximum increase in superconducting transition temperature ($T_c$) of more than 200% for $x$ = 0.06 while no change in $T_c$ is observed for the bilayers with $x\geq$ 0.20. The analysis of the critical current and kinetic inductance data suggests 2-3 unit cells thick interfacial layer electronically perturbed to have a higher $T_c$. A simple charge transfer model with cation intermixing explains the observed $T_c$ in bilayers. Still the unusually large thickness of interfacial superconducting layers can not be explained in terms of this model. We believe the stripe relaxation as well as the proximity effect also influence the superconductivity of the interface

Strain induced magnetic domain evolution and spin re-orientation transition in epitaxial manganite films

The evolution of magnetic domain structure in epitaxial La$_{0.625}$Ca$_{0.375}$MnO$_3$ films on (001) NdGaO$_3$ is monitored as a function of temperature and magnetic field using Magnetic Force Microscopy. We see two distinct regions of magnetic orientational order; one in-plane displaying contrast-less image and the other tilted away from the film plane forming a distinct stripe pattern. A strong domain splitting is observed at the boundary of two regions, which is resilient to reorientation with temperature and magnetic field. We propose a model magnetic free energy functional to explain the mechanism of domain splitting seen in manganite films

Two-dimensional electron-gas-like charge transport at magnetic Heusler alloy-SrTiO3_3 interface

We report remarkably low residual resistivity, giant residual resistivity ratio, free-electron-like Hall resistivity and high mobility ($\approx$ 10$^4$ cm$^2$V$^{-1}$s$^{-1}$) charge transport in epitaxial films of Co$_2$MnSi and Co$_2$FeSi grown on (001) SrTiO$_3$. This unusual behavior is not observed in films deposited on other cubic oxide substrates of comparable lattice parameters. The scaling of the resistivity with thickness of the films allow extraction of interface conductance, which can be attributed to a layer of oxygen vacancies confined within 1.9 nm of the interface as revealed by atomically resolved electron microscopy and spectroscopy. The high mobility transport observed here at the interface of a fully spin polarized metal is potentially important for spintronics applications

Interface superconductivity in La1.48_{1.48}Nd0.4_{0.4}Sr0.12_{0.12}CuO4_{4}/La1.84_{1.84}Sr0.16_{0.16}CuO4_{4} bilayers

We identify a distinct superconducting phase at the interface of a La$_{1.48}$Nd$_{0.4}$Sr$_{0.12}$CuO$_4$ (LNSCO)/La$_{1.84}$Sr$_{0.16}$CuO$_4$ (LSCO) epitaxial bilayer system using ac screening measurements. A model based on inter-diffusion of quasiparticles and condensate at the interface yields a thickness of $\sim$ 25 nm for the interfacial layer. Two-dimensional superconductivity of the interface layer appears to be governed by Kosterlitz-Thouless-Berezinskii transition. A parallel magnetic field suppresses the superconducting transition temperature of this layer with a pair breaking parameter $\alpha$ varying as $H^2$

Fly ash as a coating material for plasma spray coatings

The present piece of work has been undertaken to use fly-ash in developing plasma spray coatings on metal substrates. Fly-ash and fly-ash with 5% alumminum metal powder were (premixed thoroughly) plasma sprayed on stainless steel and aluminum substrates at various operating power levels of plasma torch. The coating thus produced, was characterized by thickness measurement, X-ray diffraction analysis, microscopic studies and measurement of coating-substrate adherence strength. X-ray analysis reveals the presence of alumina, silica and mullite phases. The adherence strength seems to increase with aluminum addition to flyash

Sending the message:specialized RNA export mechanisms in trypanosomes

Export of RNA from the nucleus is essential for all eukaryotic cells, with at least three major classes exported, mRNA, tRNA and rRNA. RNA export has emerged as a major step in the control of gene expression, with mRNA molecules required to complete a complex series of processing events and pass a quality control system to protect the cytoplasm from the expression of aberrant proteins. Many of these events are highly conserved across eukaryotes, reflecting their ancient origin, but significant deviation from a canonical pathway as described from animals and fungi has emerged in the trypanosomatids. With significant implications for the mechanisms that control gene expression and hence differentiation, responses to altered environments and fitness as a parasite, these deviations may also reveal additional, previously unsuspected, mRNA export pathways