High-entropy materials represent a novel type of material that has attracted extensive attention in various fields in recent years,and the high-entropy principle allows for more flexibility in designing and customizing high-entropy material performance.High-entropy materials mainly consist of high-entropy alloys(HEAs)and high-entropy ceramics.Since the discovery of the first high-entropy superconductor in 2014,superconductivity has been a key focus of research in the field of high-entropy materials.Some fascinating superconducting phenomena have been observed in some high-entropy superconductors,including robust zero resistance under high pressure,strongly coupled s-wave superconductivity,high critical current density,strong vortex pinning,and type-Ⅱ Dirac points in the band structures.However,the exploration of high-entropy materials is still in early stages,with many aspects remaining unknown.For example,the superconducting transition temperature(Tc)of most high-entropy superconductors is below 10 K,and the elemental composition and average valence electron count(VEC)play a crucial role in the Tc of high-entropy superconductors.The superconducting behavior of high-entropy alloy superconductors differs from those of conventional alloy superconductors,cuprate superconductors,Fe-based superconductors,and amorphous superconductors.This indicates that they can be considered as a distinct class of superconducting material.Furthermore,considering the excellent mechanical or thermal properties of high-entropy materials,high-entropy superconductors have considerable application potential under extreme conditions.In this paper,we briefly introduce the latest research progress of high-entropy alloy superconductors and high-entropy ceramic superconductors.Additionally,we present a preliminary overview focused on high-entropy superconductors,aiming to deepen our understanding of them.The most studied crystal structure in HEA superconductors is the body-centered cubic(BCC)structure,in which Ti,Zr,Hf,V,Nb,and Ta with a VEC value of 5 or 4 represent the dominant chemical components.The coexistence of Dirac points and superconductivity in high entropy carbide ceramics indicates that they are candidates for topological superconductors,providing a new materials platform for investigating the coupling of topological and superconductivity physics.However,the increase in mixing entropy does not have a conclusive effect on Tc.The central role of the high configurational entropy in high-entropy superconductors is to stabilize their high-symmetry crystal structures.Besides,an increase in mixing entropy appears to increase the upper critical field of high-entropy superconducting materials.This review focuses on the relevant superconducting properties of HEA and high entropy ceramic superconductors,opportunities for discovering novel high entropy superconductors and exploring their potential applications,as well as current challenges in understanding the superconductivity behavior.The study of high-entropy superconductors has just begun,and we believe that many new physical phenomena will be discovered in this field.
superconductivitytopological band structureshigh-entropy alloyshigh-entropy ceramicshigh-entropy films
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