THERMODYNAMICS OF A FRUSTRATED SPIN SYSTEM-II - EXACT CALCULATION AND SCALING

We perform exact calculations for finite triangular Ising antiferromagnetic systems with free boundaries. The thermodynamic functions of such finite systems show a systematic improvement with increasing system size, indicating a convergence towards the exact results for the infinite fully frustrated spin model. According to finite size scale theory, we show that the residual entropy and the temperature of the maximum of the specific heat scale as the relative number of boundary spins. In order to relate the thermodynamic functions of the finite systems with those of the infinite system, we use a recently proposed scaling ansatz for the free energy and the temperature. We observe both a data collapsing for different system sizes and a good agreement with the exact free energy of the thermodynamic system, which strongly support this scale assumption.