1202.4340 (T. P. Ying et al.)

Observation of superconductivity at 30 K~46 K in AxFe2Se2 (A = Li, Na,
Ba, Sr, Ca, Yb, and Eu)    [PDF]

T. P. Ying, X. L. Chen, G. Wang, S. F. Jin, T. T. Zhou, X. F. Lai, H. Zhang, W. Y. Wang

New iron selenide superconductors by intercalating smaller-sized alkali
metals (Li, Na) and alkaline earths using high-temperature routes have been
pursued ever since the discovery of superconductivity at about 30 K in (K, Rb,
or Cs)Fe2Se2, but all have failed so far. Here we demonstrate that a series of
superconductors with enhanced Tc = 30~46 K can be obtained by intercalating
metals, Li, Na, Ba, Sr, Ca, Yb, and Eu in between FeSe layers by the liquid
ammonia method at room temperature. The findings provide a new starting point
for studying the properties of these superconductors and an effective synthetic
route for the exploration of new superconductors as well.

View original: http://arxiv.org/abs/1202.4340