# The high-temperature expansion of the classical Ising model with S z^2 term - Condensed Matter > Statistical Mechanics

Abstract: We derive the high-temperature expansion of the Helmholtz free energy up tothe order \beta^{17} of the one-dimensional spin-S Ising model, with single-ionanisotropy term, in the presence of a longitudinal magnetic field. We show thatthe values of some thermodynamical functions for the ferromagnetic models, inthe presence of a weak magnetic field, are not small corrections to theirvalues with h=0. This model with S=3 was applied by Kishine et al. J.-i.Kishine et al., Phys. Rev. B, 2006, 74, 224419 to analyze experimental data ofthe single-chain magnet Mn saltmen 2 Nipac 2 py 2 PF 6 2 for T<40K. We show that for T<35 K the thermodynamic functions of the large-spin limitmodel are poor approximations to their analogous spin-3 functions.

Author: M.T. Thomaz, O. Rojas

Source: https://arxiv.org/