Optical and Resistivity Studies of Intercalated Layer Compounds.

摘要

The optical absorption of three layered compounds has been studied at 4K between 0.1 and 3.0 eV. The three compounds, TaS(1.6)Se(0.4),TaS(1.6)Se(0.4) (pyridine)(1/2), and TaS(1.6)Se(0.4) (aniline)(3/4) have layer separations of 6.14, 12.09 and 18.07 A, respectively. Well-defined, free-carrier absorption edges exist near 1.0 eV in all three materials, from which values of the plasma frequency, the interband dielectric constant, and the optical scattering time were derived using the Drude theory. As the layer spacing increases both the plasma frequency and the dielectric constant decrease. The scattering time is short and almost independent of layer spacing. The calculated d.c. resistivity is consistent with the measured value in two of the three compounds. (Modified author abstract)