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The improvement of the incorporated nanoparticle content in nanocomposite coatings is a key factor in composite electrodeposition. This paper describes a modified sediment co-deposition (SCD) technique which has been developed to produce Ni–CeO2 nanocomposite coatings, with the aim of enhancing the embedded CeO2 nanoparticle content. The maximum content of CeO2 particles in the nanocomposite coatings created using this modified SCD technique is 7·09 wt-%, which is the highest reported. A maximum microhardness of 630 HV is obtained, which is significantly greater than that observed in nanocomposite coatings fabricated using the conventional electrodeposition technique. As the wear resistance of the nanocomposite coatings increases with increasing incorporated CeO2 nanoparticle content, so this nanocomposite coating with an incorporated CeO2 nanoparticle content of 7·09 wt-% exhibits maximum wear resistance.

Electroforming is applied to fabricate microprism moulds, however only low working current density is employed because the higher current density at the edge limits the usable value of the working current density. Reduction of current density at the edge is a key in the enhancement of the working current density. In this paper, a secondary cathode was introduced to lower the edge current density. By this technique, the edge current density of the primary cathode surface is not only weakened obviously but can be even lower than that of the others. In addition, a high electrolyte flow rate has been introduced to improve working current density. Experimental results show that both the microhardness and tensile strength of the electroformed layer increase with electrolyte flowrate. By using both secondary cathode and high speed electrolyte flow, the electroforming time could be reduced significantly and mechanical properties of the electroformed layer are not adversely affected in electroforming of microprism...

Impurity scattering in a superconductor may serve as an important probe for the nature of superconducting pairing state. Here we report the impurity effect on superconducting transition temperature $T_\mathrm{c}$ in the newly discovered Cr-based superconductor K$_2$Cr$_3$As$_3$. The resistivity measurements show that the crystals prepared using high-purity Cr metal ($\geq$99.99\%) have an electron mean free path much larger than the superconducting coherence length. For the crystals prepared using impure Cr that contains various \emph{nonmagnetic} impurities, however, the $T_\mathrm{c}$ decreases significantly, in accordance with the generalized Abrikosov-Gor'kov pair-breaking theory. This finding supports a non-$s$-wave superconductivity in K$_2$Cr$_3$As$_3$., Comment: 5 pages, 3 figures, accepted for publication in SCIENCE CHINA Physics, Mechanics & Astronomy

We investigate superconductivity and transport properties of Co doped SmFe$_{1-x}$Co$_{x}$AsO system. The antiferromagnetic (AFM) spin-density wave (SDW) order is rapidly suppressed by Co doping, and superconductivity emerges as $x$ $\geq$ 0.05. $T_c$$^{mid}$ increases with increasing Co content, shows a maximum of 17.2 K at the optimally doping of $x\sim$ 0.10. A phase diagram is derived based on the transport measurements and a dome-like $T_c$ versus $x$ curve is established. Meanwhile we found that the normal state thermopower might consist of two different contributions. One contribution increases gradually with increasing $x$, and the other contribution is abnormally enhanced in the superconducting window 0.05 $\leq$ $x$ $\leq$ 0.20, and shows a dome-like doping dependence. A close correlation between $T_{c}$ and the abnormally enhanced term of thermopower is proposed.

Systematic force-deflection measurements with microcantilevers and a combinatorial-deposition method have been used to investigate the Young’s moduli of amorphous composite FeCo–SiO2 thin films as a function of film composition, with high compositional resolution. It is found that the modulus decreases monotonically with increasing FeCo content. Such a trend can be explained in terms of the metalloid atoms having a significant effect on the Young’s moduli of metal–metalloid composites, which is associated with the strong chemical interaction between the metalloid and themetallic atoms rather than that between the metallic components themselves. This work provides an efficient and effective method to study the moduli of magnetic thin films over a largecomposition coverage, and to compare the relative magnitudes of moduli for differentcompositions at high compositional resolution.

The structural, magnetic, and transport properties of Mo doping La0.67Sr0.33Mn1−xMoxO3 (x=0–0.04) manganite system have been investigated by x-ray diffraction, scanning electron microscopy, magnetization, and magnetoresistance measurements. The Mo doping in Mn site is found to lower the Curie temperature Tc slightly and induce the cluster spin glass behavior in ferromagnetic state of La0.67Sr0.33MnO3. The room temperature magnetoresistance of Mo doping La0.67Sr0.33Mn1−xMoxO3 is found to be 50% higher than that of La0.67Sr0.33MnO3 without Mo doping. The significant enhancement for room temperature magnetoresistance could likely be attributed to the presence of the cluster spin glass state caused by the Mo doping.

A series of 122 phase BaFe$_{2-x}$Ni$_x$As$_2$ ($x$ = 0, 0.055, 0.096, 0.18, 0.23) single crystals were grown by self flux method and a dome-like Ni doping dependence of superconducting transition temperature is discovered. The transition temperature $T_c^{on}$ reaches a maximum of 20.5 K at $x$ = 0.096, and it drops to below 4 K as $x$ $\geq$ 0.23. The negative thermopower in the normal state indicates that electron-like charge carrier indeed dominates in this system. This Ni-doped system provides another example of superconductivity induced by electron doping in the 122 phase.