相关论文: Hollow carbon spheres as an efficient dopant for e…

We examine the effects of the low-level substitution of S atoms by C and Si atoms on the superconductivity of H$_3$S with the $Im\bar{3}m$ structure at megabar pressure. The hole doping can fine-tune the Fermi energy to reach the electronic…

We present details of synthesis optimization and physical properties of nearly single phase carbon doped MgB2 with a nominal stoichiometry of Mg(B{0.8}C{0.2})2 synthesized from magnesium and boron carbide (B4C) as starting materials. The…

It has been shown that graphene doping is sufficient to lead to an improvement in the critical current density - field performance (Jc(B)), with little change in the transition temperature in MgB2. At 3.7 at% graphene doping of MgB2 an…

We report on the preparation of dense monofilamentary MgB2/Ni and MgB2/Fe tapes with high critical current densities. In annealed MgB2/Ni tapes, we obtained transport critical current densities as high as 2.3*105 A/cm2 at 4.2 K and 1.5 T,…

We fabricated (Ba,Na)Fe2As2 superconducting wires using the powder-in-tube method and hot isostatic pressing. By improving powder synthesis processes compared with previous studies, highly pure raw materials for the wire fabrication were…

We use computational screening to systematically investigate the use of transition metal doped carbon nanotubes for chemical gas sensing. For a set of relevant target molecules (CO, NH3, H2S) and the main components of air (N2, O2, H2O), we…

In a recent Physical Review Letter Kortus et al. claim that the observed decrease of $T_c$ in Al and C doped MgB$_2$ samples is mainly due to the band filling by the electron doping but for a fuller understanding of the different behavior…

The upper critical field Hc2||c(0) of 85 kOe in Mg(B0.94C0.06)2 single crystals, determined from torque measurements, is more than twice as large as that one of 31 kOe in unsubstituted MgB2. Anisotropy of Hc2 increases from about 3.4 near…

The paper reports the first successful fabrication of MgB2 superconducting tape using a flexible metallic substrate as well as its strong pinning force, which was verified by direct measurement of transport critical current density. The…

Iron-based superconductors have been considered to be very promising in high-field applications, for which multifilamentary wire and tape conductors with high mechanical strength are essential. In this work, 7-,19- and 114-filament…

Point-contact measurements on the carbon-substituted Mg(B$_{1-x}$C$_x$)$_2$ filament/powder samples directly reveal a retention of the two superconducting energy gaps in the whole doping range from $x = 0$ to $x \approx 0.1$. The large gap…

High energy milling of MgB2 pre-reacted powder renders the material largely amorphous through extreme mechanical deformation and is suitable for mechanically alloying MgB2 with dopants including carbon. Bulk samples of milled C and MgB2…

A comprehensive study of the effects of carbohydrate doping on the superconductivity of MgB2 has been conducted. In accordance with the dual reaction model, more carbon substitution is achieved at lower sintering temperature. As the…

We found that the transport Jc of the ex-situ PIT processed (Ba,K)Fe2As2 (Ba-122) wire with single Ag sheath can be significantly enhanced by repeating the combined process of rolling and heat treatment. The transport Jc (4.2 K and 10 T) of…

We report a significant enhancement of the upper critical field $H_{c2}$ of different $MgB_2$ samples alloyed with nonmagnetic impurities. By studying films and bulk polycrystals with different resistivities $\rho$, we show a clear trend of…

Tuning the charge carrier density of two-dimensional (2D) materials by incorporating dopants into the crystal lattice is a challenging task. An attractive alternative is the surface transfer doping by adsorption of molecules on 2D crystals,…

Observations of diffuse clouds showed that they contain a number of simple hydrocarbons (e.g. CH, C$_2$H, (l- and c-)C$_3$H$_2$, and C$_4$H) in abundances that may be difficult to understand on the basis of conventional gas-phase chemical…

The ultrathin nature of two-dimensional monolayer semiconductors yields optoelectronic properties which are highly responsive to changes in free-carrier density, making it imperative to masterfully control their doping levels. We report a…

Carbon-substituted MgB2 single crystals, Mg(B_1-xC_x)_2 of 0.3-1.0 mm size were grown for x=0.02-0.15 by a high-pressure technique. The doping dependence of lattice constants studied in a range of x=0.0-0.2 shows a monotonic decrease in a,…

Highly dense nanocrystalline MgB_2 bulk superconductors with distinctly improved pinning were prepared by mechanical alloying of Mg and B powders and hot compaction at ambient temperatures. The nanocrystalline samples reveal high critical…