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
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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U2 - 10.1016/j.physc.2009.12.067
DO - 10.1016/j.physc.2009.12.067
M3 - Article
AN - SCOPUS:78649710936
VL - 470
SP - S633-S634
JO - Physica C: Superconductivity and its Applications
JF - Physica C: Superconductivity and its Applications
SN - 0921-4534
IS - SUPPL.1
ER -