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

Global course of Engineering and Science

Research output: Contribution to journal › Article

2 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 1

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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

Cite this

Katsura, Y., Yamamoto, A., Ogino, H., Horii, S., Shimoyama, J. I., Kishio, K., & Takagi, H. (2010). On the possibility of MgB₂-like superconductivity in potassium hexaboride. Physica C: Superconductivity and its applications, 470(SUPPL.1), S633-S634. https://doi.org/10.1016/j.physc.2009.12.067

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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.",

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AU - Kishio, Kohji

AU - Takagi, Hidenori

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10.1016/j.physc.2009.12.067