title: Unconventional superconductivity in electron-doped layered Li0.48(THF)yHfNCL.
abstract: We report magnetic susceptibility measurements on a layered superconductor Li0.48(THF)0.3HfNCl having Tc approximately 26 K. The present study revealed that (a) the Fermi level density of states is small, N*(EF) approximately 0.25 states/(eV spin f.u.), (b) mass enhancement is negligible, gamma; approximately 1, (c) electron-phonon coupling is weak, lambda(ep)<<1, (d) exchange enhancement is negligible, 1/(1+F(a)0) approximately 1, and (e) electronic density parameter is large, r(2D)s approximately 10.3 (i.e., low-carrier density). It is difficult to explain the origin of the high Tc in terms of the conventional phonon (BCS) mechanism of superconductivity.
authors: Department of Physics, Tokyo Metropolitan University, Minami-osawa, Hachi-oji, Tokyo 192-0397, Japan.
authors: H
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authors: Tou
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authors: Maniwa
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authors: Koiwasaki
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authors: Yamanaka