A theoretical study of the extinction of antiferromagnetic order by holes and dilution in

We have used the quasi-two-dimensional Heisenberg antiferromagnetic model to explain the extinction of long-range order by holes and dilution in La 2 − x Sr x Cu 1 − z Zn z O 4 . An analytical expression is obtained for the Néel temperature T N ( x , z ) by using the Green’s-function formalism with random phase approximation (RPA). The expression for the Néel temperature T N ( x , z ) is a function of concentration of holes x and dilution z . To treat the dilution effect in CuO 2 plane (XY), we use three different approximations for percolation. The frustration effect is induced by interplane coupling which depends linearly on the doping concentration x . We have explained qualitatively the non-monotonic and reentrant behavior of T N ( x , z ) which was observed experimentally by Hücker [M. Hücker, V. Kataev, J. Pommer, J. Harass, A. Hosni, C. Pflitsch, R. Gross, B. Buchner, Phys. Rev. B 59 (1999) R725].