A fresh class of superconducting and hard pentaborides  

作　　者：Hui Xie Hong Wang Fang Qin Wei Han Suxin Wang Youchun Wang Fubo Tian Defang Duan 

机构地区：[1]College of Physics and Electronic Engineering,Hebei Normal University for Nationalities,Chengde 067000,China [2]College of Physics and Electronic Engineering,Linyi University,Linyi 276000,China [3]College of Physics,Jilin University,Changchun 130012,China

出　　处：《Matter and Radiation at Extremes》2023年第5期89-95,共7页极端条件下的物质与辐射（英文）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.12104127 and 22131006);the Doctoral Starting Up Foundation of Hebei Normal University for Nationalities(Grant No.DR2020001);the Clean Energy(Carbon Peaking and Carbon Neutrality)Industry Research Institute of Chengde(Grant No.202205B090);the Natural Science Foundation of Shandong Province(Grant No.ZR2020QA060)。

摘　　要：On the basis of the current theoretical understanding of boron-based hard superconductors under ambient conditions,numerous studies have been conducted with the aim of developing superconducting materials with favorable mechanical properties using boron-rich compounds.In this paper,first-principles calculations reveal the existence of an unprecedented family of tetragonal pentaborides MB_(5)(M=Na,K,Rb,Ca,Sr,Ba,Sc,and Y),comprising B_(20)cages and centered metal atoms acting as stabilizers and electron donors to the boron sublattice.These compounds exhibit both superconductivity and high hardness,with the maximum superconducting transition temperature T_(c)of 18.6 K being achieved in RbB5 and the peak Vickers hardness Hv of 35.1 GPa being achieved in KB_(5)at 1 atm.The combination of these properties is particularly evident in KB_(5),RbB5,and BaB5,with Tc values of∼14.7,18.6,and 16.3 K and H_(v)values of∼35.1,32.4,and 33.8 GPa,respectively.The results presented here reveal that pentaborides can provide a framework for exploring and designing novel superconducting materials with favorable hardness at achievable pressures and even under ambient conditions.

关 键 词：BORIDE BORON SUPERCONDUCTING 

分 类 号：TG14[一般工业技术—材料科学与工程]