Superconductivity in Li-doped {alpha}-rhombohedral boron

Journal Article · Sun May 01 00:00:00 EDT 2011 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.83.184507· OSTI ID:21544763

Nagatochi, T; Sumiyoshi, A; Kimura, K ^[1]; Hyodo, H; Soga, K ^[2]; Sato, Y; Terauchi, M ^[3]; Esaka, F ^[4]

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1. Department of Advanced Materials Science, University of Tokyo (Japan)
2. Department of Materials Science and Technology, Tokyo University of Science (Japan)
3. Institute for Multidisciplinary Research for Advanced Materials, Tohoku University (Japan)
4. Japan Atomic Energy Agency (Japan)

Metal transition and superconductivity were observed in Li-doped {alpha}-rhombohedral boron ({alpha}-B{sub 12}). The authors have established a purification method and obtained a large amount of high-purity {alpha}-B{sub 12} powder. Li doping into purified {alpha}-B{sub 12} was attempted by vapor diffusion processing (VDP) in a Mo or Ta tube. Li-doped {alpha}-B{sub 12} contained metallic glittering particles. Meissner effects were observed in such a compound with the nominal composition Li{sub x}B{sub 12} (x = 1.0, 1.4, 1.5, 1.7, or 2.5) (T{sub c} = 3.2-7 K). As for Li{sub 2.5}B{sub 12}, the temperature dependence of its electrical conductivity indicates a metallic character and its electrical resistivity drop is detected near the Meissner temperature. The existence of Li and Fermi edges in Li-doped {alpha}-B{sub 12} crystals was verified by transmission electron microscopy-electron energy loss spectroscopy (TEM-EELS). Lattice expansion, which is a well-known indicator of metal doping into a crystal, was also observed. Thus, Li doping into {alpha}-B{sub 12} was successfully achieved. Our work also suggests that it is possible to dope a larger amount of Li into {alpha}-B{sub 12} and to increase its T{sub c}.

• OSTI ID: 21544763
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 83, Issue 18; Other Information: DOI: 10.1103/PhysRevB.83.184507; (c) 2011 American Institute of Physics; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BORON
CRYSTALS
DIFFUSION
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRONS
ENERGY-LOSS SPECTROSCOPY
EXPANSION
LITHIUM ADDITIONS
METALS
PURIFICATION
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
TRANSMISSION ELECTRON MICROSCOPY
TRIGONAL LATTICES
ALLOYS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
LEPTONS
LITHIUM ALLOYS
MATERIALS
MICROSCOPY
PHYSICAL PROPERTIES
SEMIMETALS
SPECTROSCOPY