THE SPIN SUSCEPTIBILITY OF SINGLET CORRELATED OXYGEN BAND IN LA2-XSRXCUO4

We have shown that the unconventional temperature dependence of the st atic susceptibility chi(T) of the perovskite high-T-c superconductors above the superconducting transition temperature T-c can be explained in terms of two relevant band models containing the singlet-correlated oxygen band and the copper character band. The usual copper-oxygen Ha miltonian containing hopping and Coulomb repulsion terms has been redu ced to an effective Hubbard-like t - t' - t '' - U-eff model to descri be the low-energy properties. The unusual behaviour of the susceptibil ity is due to thermally activated oxygen holes coming into the hybridi zation singularity peak in the density of states. A possible physical origin of T-max in the temperature dependence of the susceptibility is discussed.