On the possibility of MgB2-like superconductivity in potassium hexaboride

Yukari Katsura; Ayako Yamamoto; Hiraku Ogino; Shigeru Horii; Jun Ichi Shimoyama; Kohji Kishio; Hidenori Takagi

doi:10.1016/j.physc.2009.12.067

On the possibility of MgB₂-like superconductivity in potassium hexaboride

Yukari Katsura, Ayako Yamamoto, Hiraku Ogino, Shigeru Horii, Jun Ichi Shimoyama, Kohji Kishio, Hidenori Takagi

Research output: Contribution to journal › Article › peer-review

4 Citations (Scopus)

Abstract

We discussed the possibility for occurrence of MgB₂-like superconductivity in cubic hexaboride KB₆, from experimental and theoretical points of view. We successfully synthesized KB₆ polycrystals with different K-site occupancies (84-98%). Transmission electron microscopy revealed that K-site vacancies are randomly but anisotropically distributed. Magnetization measurements showed that KB₆ is a paramagnetic metal, with a small hysteresis around ∼60 K. First-principles calculations indicated that KB₆ has conductive covalent network of boron like in MgB₂ superconductor. We found a clear difference between the Fermi surfaces of stoichiometric and hole-doped KB₆, implying a possibility for control of electronic structure for superconductivity, by introduction of K-site deficiency.

Original language	English
Pages (from-to)	S633-S634
Journal	Physica C: Superconductivity and its applications
Volume	470
Issue number	SUPPL.1
DOIs	https://doi.org/10.1016/j.physc.2009.12.067
Publication status	Published - 2010 Dec
Externally published	Yes

Keywords

Boride superconductor
Electronic structure
Hexaboride
KB
Transmission electron microscopy

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics
Energy Engineering and Power Technology
Electrical and Electronic Engineering

Access to Document

10.1016/j.physc.2009.12.067

Cite this

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title = "On the possibility of MgB2-like superconductivity in potassium hexaboride",

abstract = "We discussed the possibility for occurrence of MgB2-like superconductivity in cubic hexaboride KB6, from experimental and theoretical points of view. We successfully synthesized KB6 polycrystals with different K-site occupancies (84-98%). Transmission electron microscopy revealed that K-site vacancies are randomly but anisotropically distributed. Magnetization measurements showed that KB6 is a paramagnetic metal, with a small hysteresis around ∼60 K. First-principles calculations indicated that KB6 has conductive covalent network of boron like in MgB2 superconductor. We found a clear difference between the Fermi surfaces of stoichiometric and hole-doped KB6, implying a possibility for control of electronic structure for superconductivity, by introduction of K-site deficiency.",

keywords = "Boride superconductor, Electronic structure, Hexaboride, KB, Transmission electron microscopy",

author = "Yukari Katsura and Ayako Yamamoto and Hiraku Ogino and Shigeru Horii and Shimoyama, {Jun Ichi} and Kohji Kishio and Hidenori Takagi",

note = "Funding Information: This study was partially supported by the Japan Society for the Promotion of Science under the Grant-in-Aid for JSPS Fellows No. 18-11311, and by Grants for Special Postdoctoral Research from RIKEN, and by the Center for Nano Lithography & Analysis, the University of Tokyo, supported by MEXT, Japan.",

year = "2010",

month = dec,

doi = "10.1016/j.physc.2009.12.067",

language = "English",

volume = "470",

pages = "S633--S634",

journal = "Physica C: Superconductivity and its Applications",

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T1 - On the possibility of MgB2-like superconductivity in potassium hexaboride

AU - Katsura, Yukari

AU - Yamamoto, Ayako

AU - Ogino, Hiraku

AU - Horii, Shigeru

AU - Shimoyama, Jun Ichi

AU - Kishio, Kohji

AU - Takagi, Hidenori

N1 - Funding Information: This study was partially supported by the Japan Society for the Promotion of Science under the Grant-in-Aid for JSPS Fellows No. 18-11311, and by Grants for Special Postdoctoral Research from RIKEN, and by the Center for Nano Lithography & Analysis, the University of Tokyo, supported by MEXT, Japan.

PY - 2010/12

Y1 - 2010/12

N2 - We discussed the possibility for occurrence of MgB2-like superconductivity in cubic hexaboride KB6, from experimental and theoretical points of view. We successfully synthesized KB6 polycrystals with different K-site occupancies (84-98%). Transmission electron microscopy revealed that K-site vacancies are randomly but anisotropically distributed. Magnetization measurements showed that KB6 is a paramagnetic metal, with a small hysteresis around ∼60 K. First-principles calculations indicated that KB6 has conductive covalent network of boron like in MgB2 superconductor. We found a clear difference between the Fermi surfaces of stoichiometric and hole-doped KB6, implying a possibility for control of electronic structure for superconductivity, by introduction of K-site deficiency.

AB - We discussed the possibility for occurrence of MgB2-like superconductivity in cubic hexaboride KB6, from experimental and theoretical points of view. We successfully synthesized KB6 polycrystals with different K-site occupancies (84-98%). Transmission electron microscopy revealed that K-site vacancies are randomly but anisotropically distributed. Magnetization measurements showed that KB6 is a paramagnetic metal, with a small hysteresis around ∼60 K. First-principles calculations indicated that KB6 has conductive covalent network of boron like in MgB2 superconductor. We found a clear difference between the Fermi surfaces of stoichiometric and hole-doped KB6, implying a possibility for control of electronic structure for superconductivity, by introduction of K-site deficiency.

KW - Boride superconductor

KW - Electronic structure

KW - Hexaboride

KW - KB

KW - Transmission electron microscopy

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