We have successfully synthesized new superconductors Lix(C2H8N2)yWTe2 with 0 < x(Li) < 2.0 via the co-intercalation of ethylenediamine (EDA) together with Li into WTe2. It has been found that the maximum Tc = 3.8 K is shown at x(Li) = 0.5 in Lix(C2H8N2)yWTe2 and that only Li-intercalated samples of LixWTe2 with x(Li) ≤ 0.5 show no superconductivity above 2 K. The emergence of superconductivity above 2 K requires the increase in the electronic density of states (EDOS) at the Fermi level (EF) by the enhancement of the two-dimensionality due to the great expansion of the interlayer space between WTe2 layers through the EDA-intercalation in addition to the electron-doping through the Li-intercalation. The increase in EDOS at EF is supported by the increase in Pauli paramagnetic susceptibility. In addition, x(Li)-dependence of Tc can be also explained by the variation of EDOS at EF.
ASJC Scopus subject areas
- Physics and Astronomy(all)