On the High-Temperature Susceptibilities of the Two-Dimensional Ferromagnetic Heisenberg Spin Systems

With the honeycomb, square and triangular lattices the high-temperature susceptibilities and specific heats have been extended up to the eighth and seventh order, respectively, for general spin by means of the method of Rushbrooke and Wood with the aid of high-speed computers. Analyses of these coefficients by means of the ratio and Pade approximant methods seem to give evidences for non-divergence at finite temperatures of the high-temperature susceptibilities of the two-dimensional ferromagnetic Heisenberg spin systems contrary to the assertion of Stanley and Kaplan.