Screened moments and extrinsic in-gap states in samarium hexaboride.

Title	Screened moments and extrinsic in-gap states in samarium hexaboride.
Authors	W.T. Fuhrman; J.R. Chamorro; P.A. Alekseev; J.M. Mignot; T. Keller; J.A. Rodriguez-Rivera; Y. Qiu; P. Nikoli?; T.M. McQueen; C.L. Broholm
Journal	Nat Commun
DOI	10.1038/s41467-018-04007-z
Abstract	Samarium hexaboride (SmB) 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, 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 SmB 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.
Citation	W.T. Fuhrman; J.R. Chamorro; P.A. Alekseev; J.M. Mignot; T. Keller; J.A. Rodriguez-Rivera; Y. Qiu; P. Nikoli?; T.M. McQueen; C.L. Broholm.Screened moments and extrinsic in-gap states in samarium hexaboride.. Nat Commun. 2018;9(1):1539. doi:10.1038/s41467-018-04007-z

Related Elements

Samarium

62 Sm 150.360000000 Samarium

See more Samarium products. Samarium (atomic symbol: Sm, atomic number: 62) is a Block F, Group 3, Period 6 element with an atomic radius of 150.36. Samarium Bohr Model The number of electrons in each of samarium's shells is 2, 8, 18, 24, 8, 2 and its electron configuration is [Xe]4f⁶ 6s². The samarium atom has a radius of 180 pm and a Van der Waals radius of 229 pm. In its elemental form, samarium has a silvery-white appearance. Elemental Samarium Picture Samarium is not found as free element in nature. It is found in the minerals cerite, gadolinite, samarskite, monazite and bastnäsite. Samarium is classified as a rare earth element and is the 40th most abundant element in the Earth's crust. Samarium was discovered and first isolated by Lecoq de Boisbaudran in 1879. It is named after the mineral samarskite, the mineral from which it was isolated.

Boron

5 B 10.811000000 Boron

See more Boron products. Boron Bohr Model Boron (atomic symbol: B, atomic number: 5) is a Block P, Group 13, Period 2 element with an atomic weight of 10.81. The number of electrons in each of boron's shells is 2, 3 and its electron configuration is [He] 2s² 2p¹. The boron atom has a radius of 90 pm and a Van der Waals radius of 192 pm. Boron was discovered by Joseph Louis Gay-Lussac and Louis Jacques Thénard in 1808 and was first isolated by Humphry Davy later that year. Boron is classified as a metalloid is not found naturally on earth. Elemental Boron Along with carbon and nitrogen, boron is one of the few elements in the periodic table known to form stable compounds featuring triple bonds. Boron has an energy band gap of 1.50 to 1.56 eV, which is higher than that of either silicon or germanium. The name Boron originates from a combination of carbon and the Arabic word buraqu meaning borax.