  We consider the competition of magnetic and charge ordering in high-Tc
cuprates within the framework of the simplified static 2D spin-pseudospin
model. This model is equivalent to the 2D dilute antiferromagnetic (AFM) Ising
model with charged impurities. We present the mean-field results for the system
under study and make a brief comparison with classical Monte Carlo (MC)
calculations. Numerical simulations show that the cases of strong exchange and
strong charge correlation differ qualitatively. For a strong exchange, the AFM
phase is unstable with respect to the phase separation (PS) into the charge and
spin subsystems, which behave like immiscible quantum liquids. An analytical
expression was obtained for the PS temperature.
