We report the effect of Re doping in the prototype transition metal silicide W_(5)Si_(3).Structural analysis shows that Re can substitute up to 20%of W in W_(5)Si_(3)and its incorporation leads to an anisotropic shrin...We report the effect of Re doping in the prototype transition metal silicide W_(5)Si_(3).Structural analysis shows that Re can substitute up to 20%of W in W_(5)Si_(3)and its incorporation leads to an anisotropic shrink-age of the tetragonal lattice.T_(c) of W_(5−x)Re_(x)Si_(3)is strongly enhanced with increasing Re content x from 2.45 K(x=0)to 6.36 K(x=1)and higher that of isostructural Mo5−xRexSi_(3)with the same valence electron count.This T_(c) enhancement is accompanied by a drastic increase in the upper critical field and attributed to the enhancement of electron-phonon coupling caused by doping-induced phonon softening.Theoretical calculations suggest that the electronic structure of undoped W_(5)Si_(3)is characterized by strong Z_(2) invariants(1;000)and this topological character is presumably preserved upon Re doping.Our study indicates that chemical doping provides a facile way to optimize superconductivity in topological tran-sition metal silicides.展开更多
基金support by the foundation of Westlake University and the Service Center for Physical Sciences for technical assistance in SEM measurementsZhejiang University was supported by the National Natural Science Foundation of China(12050003).
文摘We report the effect of Re doping in the prototype transition metal silicide W_(5)Si_(3).Structural analysis shows that Re can substitute up to 20%of W in W_(5)Si_(3)and its incorporation leads to an anisotropic shrink-age of the tetragonal lattice.T_(c) of W_(5−x)Re_(x)Si_(3)is strongly enhanced with increasing Re content x from 2.45 K(x=0)to 6.36 K(x=1)and higher that of isostructural Mo5−xRexSi_(3)with the same valence electron count.This T_(c) enhancement is accompanied by a drastic increase in the upper critical field and attributed to the enhancement of electron-phonon coupling caused by doping-induced phonon softening.Theoretical calculations suggest that the electronic structure of undoped W_(5)Si_(3)is characterized by strong Z_(2) invariants(1;000)and this topological character is presumably preserved upon Re doping.Our study indicates that chemical doping provides a facile way to optimize superconductivity in topological tran-sition metal silicides.
