Superconductivity in A1.5phenanthrene (A=Sr,Ba).

Authors :: Wang, X. E
Yan, Y. J.
Gui, Z.
Liu, R. H.
Ying, J. J.
Luo, X. G.
Chen, X. H.
Source :: Physical Review B: Condensed Matter & Materials Physics. Dec2011, Vol. 84 Issue 21, p214523-1-214513-4. 4p.
Publication Year :: 2011
Abstract: We discover superconductivity in alkali-earth metal-doped phenanthrene. The superconducting critical temperatures Tc are 5.6 and 5.4 K for Sr1.5phenanthrene and Ba1.5phenanthrene, respectively. The shielding fraction of Ba1.5phenanthrene exceeds 65%. The Raman spectra show 8 and 7 cm-1/electron downshifts for the mode at 1441 cm-1 due to the charge transfer to organic molecules from the dopants of Ba and Sr. Similar behavior has been observed in A3phenanthrene and A3C60 (A = K and Rb). The positive-pressure effect in Sr1.5phenanthrene and Ba1.5phenanthrene together with the lower Tc with a larger lattice indicates unconventional superconductivity in this organic system. [ABSTRACT FROM AUTHOR]