Abstract
Fluorescence carbon Ka x-ray emission spectra (XES) of low-dimensional charge transfer salts [(TMTSF)(2)PF6, (BETS)(2)FeBr4, and (CPDT-STE) (TCNQ)] are presented. The Fermi energy positions are determined for these spectra using XPS binding energies of the C 1s core level. The absence of metallic Fermi edges in the carbon K alpha YES data is reminiscent of Luttinger-liquid behavior predicted for one-dimensional metals, but the observed suppression of spectral weight near the Fermi level occurs on a surprisingly large energy scale. An additional low-energy subband found in carbon K alpha XES of (BEDT-TTF)(4)[(H3O)Fe(C2O4)(3)]C5H5N is attributed to strong cation-anion-interaction in this organic superconductor.