Date of Original Version
The problem of the critical behavior of the spin‐1/2 Heisenberg ferromagnetic chain has challenged many research workers since 1964. We discuss the critical exponents α and γ recently determined by Schlottmann and by Takahashi and Yamada in the context of previously known T c =0 critical properties of the 1D s=1/2 X X Z model and the classical Heisenberg model, and we comment on the manifest breakdown of scaling in the s=1/2 Heisenberg ferromagnet.
Jill C. Bonner and Gerhard Müller. Breakdown of scaling in the spin-1/2 Heisenberg ferromagnet. J. Appl. Phys. 61 (1987), 4429-4431.
Available at: http://dx.doi.org/10.1063/1.338399