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Journal articles
Screened moments and extrinsic in-gap states in samarium hexaboride
Abstract : Samarium hexaboride (SmB$_6$) is a Kondo insulator, with a narrow gap due to hybridization between localized and conduction electrons. Despite being an insulator, many samples show metal-like properties. Rare-earth purification is exceedingly difficult, and nominally pure samples may contain 2% or more of impurities. Here to determine the effects of rare-earth doping on SmB$_6$, we synthesized and probed a series of gadolinium-doped samples. We found a relationship between specific heat and impurity moment screening which scales systematically. Consistent with this finding, our neutron scattering experiments of a high purity sample of doubly isotopic $^{154}$Sm$^{11}$B$_6$ show no intrinsic excitations below the well-established 13 meV spin-exciton. The result of introducing impurities into a Kondo insulator is incompletely understood, but it is clear from our measurements that there is a systematic relationship between rare-earth impurities and metal-like properties in SmB$_6$.
https://hal-cea.archives-ouvertes.fr/cea-01880885
Contributor : Bruno Savelli <>
Submitted on : Tuesday, September 25, 2018 - 11:46:23 AM
Last modification on : Monday, February 10, 2020 - 6:14:04 PM
Contributor : Bruno Savelli <>
Submitted on : Tuesday, September 25, 2018 - 11:46:23 AM
Last modification on : Monday, February 10, 2020 - 6:14:04 PM
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