Temperature-dependent optical conductivities and direct-current resistivity of c-axis oriented superconducting (TC = 39.6K) films (about 450nm) were measured. The normal state ab-plane optical conductivities could be described by the Drude model, with a temperature-independent Drude plasma frequency of Ω(p,D) = 13600/cm or 1.68eV. The normal state resistivity was fitted by the Bloch-Gruneisen formula with an electron-phonon coupling constant of 0.13. The optical conductivity spectra below TC of the films suggest that MgB2 was a multigap superconductor.

Optical Properties of c-Axis Oriented Superconducting MgB2 Films. J.J.Tu, G.L.Carr, V.Perebeinos, C.C.Homes, M.Strongin, P.B.Allen, W.N.Kang, E.M.Choi, H.J.Kim, S.I.Lee: Physical Review Letters, 2001, 87[27], 277001 (3pp)