Performance of MgB2 superconducting wire fabricated with non-identical Mg particles

Core densification in superconducting wire is highly desirable for obtaining high performance superconducting wires. Since voids hinder current flow in the superconducting core and they directly affect electrical property. In this study, we proposed a magnesium powder blending to regulate the porous properties. Our study delved deeper into the relationship between various particle parameters (such as particle size and distribution), impurities (MgO and Mg(OH)2), superconducting transition temperature, and current carrying capacity for MgB2 superconducting wires. We found a significant correlation between these factors and the porous properties. In particular, the blending of raw powders having spherical shape enables tuning of morphological structures and crystallinities inside cores of the power-in-tube processed MgB2 wires, resulting in superior superconducting properties. Our finding provides in-depth insights of methodological approaches towards more widespread use of superconducting materials and their applications

Evaluation of in-plane and out-of-plane crystallinities with residual amorphous phases for MgB2 superconductor

We focus on in-plane and out-of-plane crystallinities of the MgB2 superconductor. These two structural properties were evaluated in terms of peak broadening at lower angles in the X-ray diffraction. The angular behavior of the in-plane and out-of-plane peaks was used to compare it with the corresponding behavior estimated in the case of several crystallite sizes (that affect the in-field superconductivity of MgB2). We propose that this comparison allows a simple evaluation to provide insight into the individual influences of in-plane and out-of-plane crystallinities on the in-field critical current density (without needing to calculate numerical values of crystallite sizes and lattice strains of fabricated MgB2 materials). For this study, we used MgB2 samples sintered at different temperatures. The sintering conditions affected not only the crystallinities but also the phase compositions. The behavior of the compositions, including amorphous phases, was also evaluated by using a quantitative analysis for X-ray diffraction results

Evaluation and control of residual amorphous phases in carbon-doped MgB₂ superconductors

Evaluation and control of amorphous phases in materials are very important for optimizing their properties. Herein, we focus on polycrystalline MgB materials prepared with hydrocarbon doping and study the effects of residual amorphous impurities on the superconducting performance. Carbon is known to be an effective element for enhancing the transport critical current under an external magnetic field. The doped samples were prepared under two different nominal conditions, MgB (C H ) and MgB (C H ) , which respectively correspond to additional and substitutional type doping of the MgB composition. Regardless of the doping type, both fabrication methods retarded the formation of the MgB phase due to the dopant, leading to an increase in amorphous impurities. However, the apparent phenomena that arise from the additional and substitutional types are still elusive. Ultimately, the structural differences due to the impurity effects caused significant changes in the transport critical current performance. The present quantitative analysis of the amorphous impurities thus paves the way to further optimize the doping methodology for MgB superconducting materials. 2 2 16 10 x/16 2−x 16 10 x/16 2 2