MgB2 tape samples with simultaneous additions of acetone and La2O3 were prepared by an in？situ processed powder-in-tube method. Compared to the pure and single doped tapes, both transport Jc and fluxing pinning are g...MgB2 tape samples with simultaneous additions of acetone and La2O3 were prepared by an in？situ processed powder-in-tube method. Compared to the pure and single doped tapes, both transport Jc and fluxing pinning are greatly improved by acetone and La2O3 codoping. Acetone supplies carbon into the MgB2 crystal lattice and increases the upper critical field, while the La2O3 reacts with B to form LaB6 nanoparticles as effective flux pining centers. The improvement of the superconducting properties in codoped tapes can be attributed to the combined effects of improvement in Hc2 and flux pinning.展开更多
We fabricated a c−axis aligned Sr_(0.6)K_(0.4)Fe_(2)As_(2)superconductor using a two−step magnetic field procedure.The effect of the magnetic fields on the structure and superconducting properties of Sr_(0.6)K_(0.4)Fe...We fabricated a c−axis aligned Sr_(0.6)K_(0.4)Fe_(2)As_(2)superconductor using a two−step magnetic field procedure.The effect of the magnetic fields on the structure and superconducting properties of Sr_(0.6)K_(0.4)Fe_(2)As_(2) is investigated using x−ray diffraction and magnetic measurements.The degree of orientation of the samples is about 0.39 for the c axis and 0.51 for ab-plane orientation,as evaluated from the Lotgering factor of x-ray diffraction.This technology may be useful in a variety of potential applications,including preparing iron-based superconducting bulks and wires with high critical currents.展开更多
基金Supported by the Beijing Municipal Natural Science Foundation under Grant No 2102045, the National Natural Science Foundation of China under Grant No 50802093, and the National Basic Research Program of China under Grant No 2011CB605905.
文摘MgB2 tape samples with simultaneous additions of acetone and La2O3 were prepared by an in？situ processed powder-in-tube method. Compared to the pure and single doped tapes, both transport Jc and fluxing pinning are greatly improved by acetone and La2O3 codoping. Acetone supplies carbon into the MgB2 crystal lattice and increases the upper critical field, while the La2O3 reacts with B to form LaB6 nanoparticles as effective flux pining centers. The improvement of the superconducting properties in codoped tapes can be attributed to the combined effects of improvement in Hc2 and flux pinning.
基金by the National Basic Research Program of China under Grant No 2011CBA00105the National Natural Science Foundation of China under Grant Nos 51002150 and 51025726。
文摘We fabricated a c−axis aligned Sr_(0.6)K_(0.4)Fe_(2)As_(2)superconductor using a two−step magnetic field procedure.The effect of the magnetic fields on the structure and superconducting properties of Sr_(0.6)K_(0.4)Fe_(2)As_(2) is investigated using x−ray diffraction and magnetic measurements.The degree of orientation of the samples is about 0.39 for the c axis and 0.51 for ab-plane orientation,as evaluated from the Lotgering factor of x-ray diffraction.This technology may be useful in a variety of potential applications,including preparing iron-based superconducting bulks and wires with high critical currents.
