Thermodynamics of the one-dimensional s=1 XXZ Heisenberg model:   analytical results
  We apply the results recently derived by Rojas et al. to derive the beta-expansion of the Helmholtz free energy of the spin-1 XXZ Heisenberg model up to 5th order in beta. The analytical expansion obtained is valid for all phases of this model. Our curves of the specific heat fit well Bloete's numerical results in the high temperature regime. 
O. Rojas, E. V. Correa-Silva, W. A. Moura-Melo, S. M. de Souza, M. T.   Thomaz