Complex critical magnetic behaviour in three dimensions

Three-dimensional (3D) Ising universality in magnets and critical indices at fluid–fluid phase transition

“…Although Rb 2 ZnCl 4 was considered to belong to the 3D-XY universality class in[33], these critical exponents are closer to the recent 3D Ising values[1]. The critical exponent ¼ 1.228 AE 0.014 for YIG (Y 3 Fe 5 O 12 )[35] is closer to the 3D Ising value ¼ 5/4[1] than to the mean field value ¼ 1 or the Heisenberg value ¼ 4/3. The critical exponent ¼ 0.365 AE 0.015 was obtained for NiCO3 …”

“…The wavelength and frequency dependence of neutrons magnetically scattered from iron was studied [26] [35].…”

Dimensionality crossover upon magnetic saturation in Fe, Ni and Co

“…Second, continuous symmetry applies not only asymptotically for T-T c but sets in at a well-defined crossover temperature above the critical point [12]. This is approximately at the change from Curie-Weiss susceptibility to critical susceptibility.…”