MgO nanorods with an average diameter of 30 nm and lengths of
2-3 µm have been incorporated into (Bi, Pb)-2223/Ag tapes. X-ray
diffraction analysis shows that a small addition of MgO nanorods does not
obstruct the formation of (Bi, Pb)-2223 phase. Scanning electron microscopy
images show that the size of the (Bi, Pb)-2223 grains and the degree of
texture in the samples doped with 1 wt% of MgO nanorods are improved.
Transmission electron microscopy
observation also shows that the MgO nanorods do not agglomerate or grow during
the sintering process. The transport critical current densities of the samples
doped with 1 wt% of MgO nanorods are enhanced noticeably at high temperatures
and magnetic fields and the irreversibility line of the samples doped with
1 wt% of MgO nanorods shifts to higher temperatures and magnetic fields as
compared with the undoped samples. The possible pinning mechanism of the
samples doped with MgO nanorods is discussed. The results reveal that the
introduction of MgO nanorods as columnar defects can effectively enhance the
flux pinning.
The mechanical properties, thermodynamic properties and electronic structure of Mo 1−x Ta x (Mo-Ta) alloys (x=0, 0.0625, 0.125, 0.25, 0.3125, 0.5 and 1) were calculated by using firstprinciples. The electronic structure of Mo-Ta alloys was analysed by the projected density of states (PDOS). The low temperature heat capacity was estimated by Fermi energy and Debye temperature. It is shown that the formation enthalpy will decrease with the increase of Ta content, and the cohesive energy will increase with the increase of the Ta content. On the other hand, the addition of Ta atoms will reduce the strength and improve the ductility of Mo-Ta alloys, the Debye temperature will decrease and the low temperature heat capacity will be improved with the increase of the Ta content. All these results will be useful for the research of new plasma grid (PG) materials, which is mainly used in neutral beam injection (NBI) systems to produce negative hydrogen ions.
MgO nanorods with the average diameter of 30 nm and the length of 2 to 3 mm have been incorporated into (Bi, Pb)-2223 superconductors. The differential thermal analysis (DTA) measurements show that the addition of MgO nanorods results in the lowering of the melting point of the samples, which indicates that the optimum formation temperature of (Bi, Pb)-2223 phase is reduced. X-ray diffraction (XRD) analysis manifests that a small addition of MgO nanorods does not obstruct the formation of (Bi, Pb)-2223 phase. Furthermore, the transmission electron microscopy (TEM) observation shows that the MgO nanorods do not agglomerate or grow during the sintering process, which is crucial to the further application of MgO nanorod doping in (Bi, Pb)-2223/Ag tapes. The ac susceptibility measurements indicate that a small addition of MgO nanorods enhances the intergrain critical current density J c significantly. The enhancement of J c originates from the improvement of intergrain coupling due to the MgO nanorod doping.
The lattice structure, mechanical properties, electronic structure and thermodynamic properties of W1−xVx alloys (x = 0, 0.0625, 0.125, 0.25, 0.3125, 0.5 and 1) were calculated and simulated by first-principles method based on DFT. The mechanical properties including Poisson’s ratio, elastic moduli and B/G ratio were analysed via V concentration. The simulated results showed the ductility of alloys getting improved while the strength decreased with the addition of vanadium. And we calculated the anisotropy of Young’s modules and ideal tensile strength. The projected density of states is calculated to analyse the electronic structure. Furthermore, thermodynamic properties like Debye temperature and low temperature heat capacity were also calculated in this work. All the results can provide reference for selecting plasma facing materials in fusion reactor design.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.