Interpretation of experimental results of spin chains with weak interchain interaction

Experimental results concerning magnetic susceptibility and heat capacity of the CuSb2O6 crystal, where the Cu2+ ions form chains interacting with strong short range antiferromagnetic (AF) intrachain and weak AF interchain interactions, can be interpreted in terms of small rings to which the large chains are split and rejoined. The weak interchain interaction causes a small energy gap between the ground and the first excited states of CuSb2O6. The agreement between theory and experiment is remarkable. The fitting of the theoretical to the experimental results, permits the determination of the coupling constants of the Heisenberg Hamiltonian and the Lande factors along the symmetry axes of the crystal.