Polarized x-ray emission and absorption spectra of MgB2 -: art. no. 165114

The polarized K-emission and absorption spectra for MgB2 have been calculated using the tight-binding linear muffin-tin orbitals method. Within the dipole approximation a strong anisotropy is found. The core-hole effect has also been included in the calculation of the absorption spectra shifting the empty p-like states of Mg significantly towards lower energies in comparison with those of the ground state calculation. For the K-absorption spectrum of B the effect is much weaker in which the screening of the 1s core hole is much more efficient due to the higher density of states at the Fermi level in the ground state. The K-absorption process is predicted have a tendency to lower the critical temperature T-c of the superconductivity.