TY - JOUR
T1 - Sc-Zr-Nb-Rh-Pd and Sc-Zr-Nb-Ta-Rh-Pd High-Entropy Alloy Superconductors on a CsCl-Type Lattice
AU - Stolze, Karoline
AU - Tao, Jing
AU - Von Rohr, Fabian O.
AU - Kong, Tai
AU - Cava, Robert J.
N1 - Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/2/13
Y1 - 2018/2/13
N2 - We have synthesized previously unreported high-entropy alloys (HEAs) in the pentanary (ScZrNb)1-x[RhPd]x and hexanary (ScZrNbTa)1-x[RhPd]x systems. The materials have CsCl-type structures and mixed site occupancies. Both HEAs are type-II superconductors with strongly varying critical temperatures (Tc's) depending on the valence electron count (VEC); the Tc's increase monotonically with decreasing VEC within each series, and do not follow the trends seen for either crystalline or amorphous transition metal superconductors. The (ScZrNb)0.65[RhPd]0.35 HEA with the highest Tc, -9.3 K, also exhibits the largest μ0Hc2(0) = 10.7 T. The pentanary and hexanary HEAs have higher superconducting transition temperatures than their simple binary intermetallic relatives with the CsCl-type structure and a surprisingly ductile mechanical behavior. The presence of niobium, even at the 20% level, has a positive impact on the Tc. Nevertheless, niobium-free (ScZr)0.50[RhPd]0.50, as mother-compound of both superconducting HEAs found here, is itself superconducting, proving that superconductivity is an intrinsic feature of the bulk material.
AB - We have synthesized previously unreported high-entropy alloys (HEAs) in the pentanary (ScZrNb)1-x[RhPd]x and hexanary (ScZrNbTa)1-x[RhPd]x systems. The materials have CsCl-type structures and mixed site occupancies. Both HEAs are type-II superconductors with strongly varying critical temperatures (Tc's) depending on the valence electron count (VEC); the Tc's increase monotonically with decreasing VEC within each series, and do not follow the trends seen for either crystalline or amorphous transition metal superconductors. The (ScZrNb)0.65[RhPd]0.35 HEA with the highest Tc, -9.3 K, also exhibits the largest μ0Hc2(0) = 10.7 T. The pentanary and hexanary HEAs have higher superconducting transition temperatures than their simple binary intermetallic relatives with the CsCl-type structure and a surprisingly ductile mechanical behavior. The presence of niobium, even at the 20% level, has a positive impact on the Tc. Nevertheless, niobium-free (ScZr)0.50[RhPd]0.50, as mother-compound of both superconducting HEAs found here, is itself superconducting, proving that superconductivity is an intrinsic feature of the bulk material.
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U2 - 10.1021/acs.chemmater.7b04578
DO - 10.1021/acs.chemmater.7b04578
M3 - Article
AN - SCOPUS:85042037185
SN - 0897-4756
VL - 30
SP - 906
EP - 914
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 3
ER -