ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Two-dimensional magnetic behavior in thin films and in layered magnets apparently falls into one of only two universality classes. The first is that of the 2D Ising model, characterized by a magnetization exponent β=1/8. The second, with β≈0.23, is observed in systems with planar spin symmetry. Recently it has been shown, using a modified renormalization group calculation, that β=0.23 is a property of a finite size XY model. Although there is no broken symmetry in this system, correlations below the Kosterlitz–Thouless transition temperature decay so slowly that a magnetization occurs in any realizable system, and β=0.23 is a result of two-dimensional fluctuations. By considering a large number of experimental situations we demonstrate that this rule is generally obeyed, and can be used as a test to identify two-dimensional behavior.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.353481
