DOPING DEPENDENCE OF LOCAL MAGNETIC-MOMENTS AND ANTIFERROMAGNETISM INHIGH-T(C) SUPERCONDUCTORS - ASYMMETRY BETWEEN ELECTRON AND HOLE DOPING

Using a three-band Hubbard Hamiltonian for the CuO2 planes we calculat e the doping dependence of the local magnetic moment at Cu-sites, of t he Cu-O spin singlet state and of the antiferromagnetic phase in high- T(c) superconductors. By taking into account short range magnetic orde r we obtain the observed electron-hole asymmetry of the magnetic phase diagram. Responsible for this is singlet induced frustration in hole doped systems. Our results for the critical doping at which antiferrom agnetism disappears are in good agreement with experiment.