MAGNETIC-PROPERTIES OF SINGLE-LAYERED CU-OXIDES IN THE EXTENDED T-J MODEL

A detailed comparison of the magnetic phase diagram of the single laye r cuprate materials La2-xSr2CuO4 and Tl2Ba2CuO6+x is made within the u niform metallic state of the extended t-J model. La2-xSr2CuO4 is chara cterised by strong anti-ferromagnetic correlations with the mean field anti-ferromagnetic transition persisting to a doping level approximat ely 0.2. We obtain semi-quantitative agreement with experiment outside this region. The model fails to describe the experimental trends in T l2Ba2CuO6+x, despite the fact that this material is far from the anti- ferromagnetic phase boundary. Implications of these results are discus sed.