Design of high-temperature superconductors at moderate pressures by alloying AlH3 or GaH3OA
Since the discovery of hydride superconductors,a significant challenge has been to reduce the pressure required for their stabilization.In this context,we propose that alloying could be an effective strategy to achieve this.We focus on a series of alloyed hydrides with the AMH_(6)composition,which can be made via alloying A15 AH_(3)(A=Al or Ga)with M(M=a group IIIB or IVB metal),and study their behavior under pressure.Seven of them are predicted to maintain the A15-type structure,similar to AH_(3)under pressure,providing a platform for studying the effects of alloying on the stability and superconductivity of AH_(3).Among these,the A15-type phases of AlZrH_(6)and AlHfH_(6)are found to be thermodynamically stable in the pressure ranges of 40–150 and 30–181 GPa,respectively.Furthermore,they remain dynamically stable at even lower pressures,as low as 13 GPa for AlZrH_(6)and 6 GPa for AlHfH_(6).These pressures are significantly lower than that required for stabilizing A15 AlH3.Additionally,the introduction of Zr or Hf increases the electronic density of states at the Fermi level compared with AlH3.This enhancement leads to higher critical temperatures(Tc)of 75 and 76 K for AlZrH_(6)and AlHfH_(6)at 20 and 10 GPa,respectively.In the case of GaMH_(6)alloys,where M represents Sc,Ti,Zr,or Hf,these metals reinforce the stability of the A15-type structure and reduce the lowest thermodynamically stable pressure for GaH_(3) from 160 GPa to 116,95,80,and 85 GPa,respectively.Particularly noteworthy are the A15-type GaMH_(6)alloys,which remain dynamically stable at low pressures of 97,28,5,and 6 GPa,simultaneously exhibiting high Tc of 88,39,70,and 49 K at 100,35,10,and 10 GPa,respectively.Overall,these findings enrich the family of A15-type superconductors and provide insights for the future exploration of high-temperature hydride superconductors that can be stabilized at lower pressures.
Xiaowei Liang;Xudong Wei;Eva Zurek;Aitor Bergara;Peifang Li;Guoying Gao;Yongjun Tian;
Center for High Pressure Science(CHiPS),State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,China School of Materials Science and Engineering,Henan University of Technology,Zhengzhou 450001,ChinaCenter for High Pressure Science(CHiPS),State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,ChinaDepartment of Chemistry,State University of New York at Buffalo,Buffalo,New York 14260-3000,USAPhysics Department and EHU Quantum Center,University of the Basque Country,UPV/EHU,48080 Bilbao,Spain Donostia International Physics Center(DIPC),20018 Donostia,Spain Centro de Física de Materiales CFM,Centro Mixto CSIC-UPV/EHU,20018 Donostia,SpainExtreme Conditions Physics Research Team,College of Physics and Electronic Information,Inner Mongolia Minzu University,Tongliao 028043,China
金属材料
alloyingalloyssuperconductors
《Matter and Radiation at Extremes》 2024 (001)
P.94-103 / 10
supported by the Natural Science Foundation of China(Grant Nos.52022089,52372261,52288102,and 11964026);the National Key R&D Program of China(Grant No.2022YFA1402300);the Natural Science Foundation of Hebei Province(Grant No.E2022203109);the Doctoral Fund of Henan University of Technology(Grant No.31401579);P.L.thanks the Science and Technology Leading Talents and Innovation Team Building Projects of the Inner Mongolia Autonomous Region(Grant No.GXKY22060);financial support from the Spanish Ministry of Science and Innovation(Grant No.FIS2019-105488GB-I00);the Department of Education,Universities and Research of the Basque Government and the University of the Basque Country(Grant No.IT1707-22);the National Science Foundation(Grant No.DMR-2136038)for financial support.
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