SUPEREXCHANGE COUPLING AND SPIN SUSCEPTIBILITY SPECTRAL WEIGHT IN UNDOPED MONOLAYER CUPRATES

A systematic inelastic neutron scattering study of the superexchange i nteraction in three different undoped monolayer cuprates (La2CuO4, Nd2 CuO4, and Pr2CuO4) has been performed using conventional triple axis t echnique. We deduce the in-plane antiferromagnetic (AF) superexchange coupling J which actually presents no simple relation versus crystallo graphic parameters. The absolute spectral weight of the spin susceptib ility has been obtained and it is found to be smaller than expected ev en when quantum corrections of the AF ground state are taken into acco unt.