Journal of Physics A Mathematical and General
The gap exponent Δ for the spin-s Ising model on the FCC lattice
Sati McKenzie
Abstract
High-temperature series expansions are presented for the magnetisation M(K,h) of the spin-s Ising model on the face-centred cubic lattice. Series coefficients are derived to order 13 and 5 respectively in the variables K=J/kT and h=mH/kT, for 1 / 2 <or=s<or= 9 / 2 . The data are analysed for 2 Delta - gamma , where Delta and gamma denote the gap exponent and the susceptibility exponent respectively. The estimate 2 Delta - gamma =1.890+or-0.003 satisfies the data for all s.