We have extended the series for the zero-field susceptibility of the spin-
S Ising model to eighth order in the reduced temperature
K, on the triangular, simple cubic, body-centered-cubic, and face-centered-cubic lattices. The coefficients of these series
hn(S) are expressed as simple polynomials in
X=S(S+1). For the face-centered-cubic lattice, an accurate polynomial fit to the critical point
Kc(S) is presented; and the apparent spin dependence of the critical exponent $\ensuremath{\gamma}$ is briefly discussed. The series are quite well behaved for all
S. However, the large-
S series seems to exhibit more rapid apparent convergence.
Using a renormalized linked-cluster-expansion method, we have extended to order ${\ensuremath{\beta}}^{23}$ the high-temperature series for the susceptibility $\ensuremath{\chi}$ and the second-moment correlation length $\ensuremath{\xi}$ of the spin-1/2 Ising models on the sc and the bcc lattices. A study of these expansions yields updated direct estimates of universal parameters, such as exponents and amplitude ratios, which characterize the critical behavior of $\ensuremath{\chi}$ and $\ensuremath{\xi}.$ Our best estimates for the inverse critical temperatures are ${\ensuremath{\beta}}_{c}^{\mathrm{sc}}=0.221654(1)$ and ${\ensuremath{\beta}}_{c}^{\mathrm{bcc}}=0.1573725(6).$ For the susceptibility exponent we get $\ensuremath{\gamma}=1.2375(6)$ and for the correlation length exponent $\ensuremath{\nu}=0.6302(4).$ The ratio of the critical amplitudes of $\ensuremath{\chi}$ above and below the critical temperature is estimated to be ${C}_{+}{/C}_{\ensuremath{-}}=4.762(8).$ The analogous ratio for $\ensuremath{\xi}$ is estimated to be ${f}_{+}{/f}_{\ensuremath{-}}=1.963(8).$ For the correction-to-scaling amplitude ratio we obtain ${a}_{\ensuremath{\xi}}^{+}{/a}_{\ensuremath{\chi}}^{+}=0.87(6).$
Abstract The static critical behavior of a three-dimensional decorated Ising model on a cubic lattice is investigated by the methods of computational physics. The case is considered when the exchange interaction Jn = –1 between nodal spins is antiferromagnetic and the interaction Jd between nodal spins and decorated spins varies within [–3.0; 3.0]. For various values of Jd, the ground state of the model is determined, the critical temperatures and critical exponents are calculated, and the phase diagram is constructed. It is shown that, for any ratios of exchange interactions in the model, a second-order phase transition is observed from an ordered to a paramagnetic state, and the critical exponents are close to the values for the standard Ising model.