Modeling And Photoabsorption Study of YPd_(2-x)Rh_xB_2C Superconductors

摘要

The electronic structures of six polycrystalline borocarbide superconductors YPd_(5-x)Rh_xB_3C_(0.4) (x=0, 0.05, 0.1,0.15,0.2, and 0.25) were studied by photoemission and photoabsorption spectroscopies and theoretical calculations. The valence-band (VB) photoemission spectrum is compared with the theoretical total and partial density-of-states (DOS) curves. The Pd L_3-edge x-ray absorption near edge spectra (XANES) are compared with the calculated XANES spectra for these intermetallic compounds. The decrease of the superconducting transition temperatures (T_c) with addition of Rh dopant in these compounds is due to a decrease of the total DOS at the Fermi level (E_F).