Interpretation of the experimental magnetic properties of spin 12 square lattice (K2V2O5) by means of small square lattice spin theory

Experimental results of magnetization and magnetic susceptibility of the square spin lattice can be interpreted by using a Heisenberg Hamiltonian for a small 4×4 square lattice. We find that the agreement between theory and experiments is remarkable, as in the case with the one-dimensional ring. We also treat the symmetry breaking Dzialoshinski-Moriya interaction, which is present in the 2D square lattice antiferromagnet K2V2O5, using mean field theory. Surprisingly we find good agreement between theory and experiment. By combining experimental and theoretical results one can determine the coupling constants of the Hamiltonian.