摘要
Searching for high-performance thermoelectric(TE)materials in the paradigm of narrow-bandgap semiconductors is hampered by a bottleneck.Here we report on the discovery of metallic compounds,TiFe_(x)Cu_(2x−1)Sb and TiFe1.33Sb,showing the thermopower exceeding many TE semiconductors and the dimensionless figure of merits zTs comparable with the state-of-the-art TE materials.A quasi-linear temperature(T)dependent electrical resistivity in 2–700 K and the logarithmic T-dependent electronic specific heat at low temperature coexist with the high thermopower,highlighting the strong intercoupling of the non-Fermi-liquid(NFL)quantum critical behavior of electrons with TE transports.Electronic structure analysis reveals a competition between the antiferromagnetic(AFM)ordering and Kondo-like spin compensation as well as a parallel two-channel Kondo effect.The T-dependent magnetic susceptibility agrees with the quantum critical scenario of strong local correlation.Our work demonstrates the correlation among high TE performance,NFL quantum criticality,and magnetic fluctuation,which opens up directions for future research.
基金
This work was supported by the National Key Research and Development Program of China(Nos.2018YFA0702100 and 2019YFA0704901)
National Natural Science Foundation of China(Grant Nos.92163212,51632005,U21A2054,52072234,and 51772186)
W.Z.also acknowledges the support from the Guangdong Innovation Research Team Project(No.2017ZT07C062)
Guangdong Provincial Key-Lab program(No.2019B030301001)
Shenzhen Municipal Key-Lab program(ZDSYS20190902092905285)
the Centers for Mechanical Engineering Research and Education at MIT and Southern University of Science and Technology,China.Computing resources were supported by the Center for Computational Science and Engineering at the Southern University of Science and Technology.We thank Dr.D.C.Wu at Thermo Fisher Scientific Company for assistance in performing atom-resolved EDS maps.
