Sublattice magnetization in the antiferromagnetic parent compounds of cuprate high-T-c superconductors

We have calculated the temperature dependence of the sublattice magnetizati on, M(T), in Ca(Sr)CuO2 within the framework of the spin-wave model applied to a quasi-two-dimensional Heisenberg antiferomagnet. We found that, below about T-N/2, the relative decrease of M(T) follows a power law: [M(0)-M(T) ]/ M(0) = AT(n) with n similar to 2. Such a result had already been found f or YBa2Cu3O6 and La2CuO4. The change in the magnitude of A in these compoun ds can be related to the change in their interlayer coupling constants J'. [S0163-1829(99)02930-6].