Fermi-liquid behavior in the electrical resistivity of K 3 C 60 </…
1994; American Physical Society; Volume: 50; Issue: 5 Linguagem: Inglês
10.1103/physrevb.50.3462
ISSN1095-3795
AutoresT. T. M. Palstra, A. F. Hebard, Robert C. Haddon, P. B. Littlewood,
Tópico(s)High-pressure geophysics and materials
ResumoWe report on the electrical resistivity of ${\mathrm{K}}_{3}$${\mathrm{C}}_{60}$ and ${\mathrm{Rb}}_{3}$${\mathrm{C}}_{60}$ thin films. These films, grown at elevated temperatures, are highly textured and consist of large single-crystal grains. The films exhibit metallic behavior up to 500 K, with residual resistivities of 1.2 m\ensuremath{\Omega} cm. The low-temperature (T) resistivity exhibits a ${\mathit{T}}^{2}$ dependence. We suggest that it is dominated by electron-electron interactions, and we find quantitative agreement not only with estimates based on the electron density and the bandwidth, but also with other narrow band systems. The electron-phonon interactions only become important for the resistivity above room temperature, because these phonons correspond to high-frequency vibrations of the ${\mathrm{C}}_{60}$ molecule. Nevertheless, virtual excitations of these same high-energy phonons are responsible for the superconductivity. Using similar criteria of conventional organic superconductors, we find that these materials are dominated at all temperatures by electron-phonon interactions.
Referência(s)