Critical Current Density News Today

Carbon doping has proven to be a highly effective strategy for enhancing the electrical properties of MgB2 wires, especially under a high magnetic field. However, unreacted doping material can persist as impurities due to uneven mixing or incomplete reactions, thereby detrimentally affecting electrical properties and their uniformity. In this study, we explore the application of pyrene doping to 18-multifilamentary MgB2 wires with a total length of 2.5 kilometers. The aim of this study is to min...

High critical current density (Jc) and small magnetic relaxation are crucial for technological applications of high temperature superconductors. So far, improved Jc has been reported, based on the pinning of vortices via local structural inhomogeneities in superconductors, which are induced by chemical doping, irradiation, and inclusion of non-superconducting secondary phases. In cuprates and iron-based superconductors (IBSCs), the superconducting state is induced mainly through chemical doping/...

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 temper...

Here, we report superconducting Mg11B2 wires made by using the internal Mg diffusion technique with isotopic amorphous nano boron (11B) as the precursor material. We show the influence of annealing temperature and isostatic pressure of 0.1 MPa and 1.1 GPa on Mg diffusion into 11B layer, microstructure of superconducting filament, critical current density (Jc) at 20 K and 25 K, critical temperature (Tc) and irreversible magnetic induction (Birr) in mono (single-core) - and multi-filament Mg11B2 w...

Layered crystal structures of various materials form through strong in-plane covalent and weaker out-of-plane bonding. The different bonding states can lead to the appearance of anisotropies not only of electronic/electrical and magnetic properties but also of structural disorder. A deeper understanding of the disorder anisotropy is essential to carry out structural modification and to enhance the material properties. However, in the case of multi-band MgB2 superconducting materials that have la...

It is well known that the existence of interstitial Fe is a great obstacle to enhancing the superconducting properties of the Fe(Se, Te) system. In this work, a silver and oxygen codoping effect toward enhancement of the superconductivity and flux pinning in Fe(Se, Te) bulks is reported. The oxygen ions from SeO2 can induce the precipitation of interstitial Fe as Fe2O3, thus simultaneously optimizing the superconducting properties of Fe(Se, Te) and forming extra flux pinning centers, while the e...

Powder processing by ball milling is an effective approach for materials engineering. Although various methods for material processing are available, only high-energy shaker/vibratory or planetary mills have been intensively utilized to develop mechanical milling or alloying routes for structural control of MgB2 superconducting materials. Herein, we have attempted structural modification by using a low-rotation shaker, which is categorized as a low-energy and economical mill in terms of industri...

Abstract 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 ) a...