Improving Superconducting Performance of Fe(Se, Te) with In Situ Formed Grain-Boundary Strengthening and Flux Pinning Centers.

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 SeO can induce the precipitation of interstitial Fe as FeO, thus simultaneously optimizing the superconducting properties of Fe(Se, Te) and forming extra flux pinning centers, while the existence of Ag can enhance the intergrain connections of the polycrystalline material by improving the electron transport at grain boundaries.

Boosting Superconducting Properties of Fe(Se, Te) via Dual-Oscillation Phenomena Induced by Fluorine Doping.

Fluorine-doped Fe(Se, Te) has been successfully synthesized using the melting method. A dual-oscillation effect was found in the F-doped sample, which combined both microstructural oscillation and chemical compositional oscillation. The microstructural oscillation could be attributed to alternate growth of tetragonal β-Fe(Se, Te) and hexagonal δ-Fe(Se, Te), which formed a pearlite-like structure and led to the enhancement of δ l flux pinning due to the alternating distributed nonsuperconducting δ-Fe(Se, Te) phase.

Effect of Solidification on Microstructure and Properties of FeCoNi(AlSi) High-Entropy Alloy Under Strong Static Magnetic Field.

Strong static magnetic field (SSMF) is a unique way to regulate the microstructure and improve the properties of materials. FeCoNi(AlSi) alloy is a novel class of soft magnetic materials (SMMs) designed based on high-entropy alloy (HEA) concepts. In this study, a strong static magnetic field is introduced to tune the microstructure, mechanical, electrical and magnetic properties of FeCoNi(AlSi) high-entropy alloy.