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 |
|---|---|
| Journal | Physica C: Superconductivity and its Applications |
| Volume | 470 |
| Issue number | SUPPL.1 |
| DOIs | |
| Publication status | Published - 2010 Dec |
| Externally published | Yes |
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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
On the possibility of MgB2-like superconductivity in potassium hexaboride. / Katsura, Yukari; Yamamoto, Ayako; Ogino, Hiraku; Horii, Shigeru; Shimoyama, Jun Ichi; Kishio, Kohji; Takagi, Hidenori.
In: Physica C: Superconductivity and its Applications, Vol. 470, No. SUPPL.1, 12.2010.Research output: Contribution to journal › Article
}
TY - JOUR
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
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
UR - http://www.scopus.com/inward/record.url?scp=78649710936&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78649710936&partnerID=8YFLogxK
U2 - 10.1016/j.physc.2009.12.067
DO - 10.1016/j.physc.2009.12.067
M3 - Article
AN - SCOPUS:78649710936
VL - 470
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - SUPPL.1
ER -