The induced by dipole-dipole coupling anisotropy constant is expressed as a sum of two contributions. The first one does not depend on the film thickness and the details of the magnetization distribution within the film and is expressed via the magnetization dispersion. The second one connected with the magnetization fluctuations depends on relationship between the film thickness and the characteristic magnetization inhomogeneity sizes. For the randomly inhomogeneous films the both contributions to the uniaxial anisotropy constant K_u are proportional to the volume dispersion of magnetization. For the granular films with periodically as well as randomly situated granules an exponential low of approaching of the dependence K_U(L) to saturation is predicted. Whereas for the columnar films it is typical more slow approach to saturation by the low 1/L for periodical structure or 1/L~2 for the random columnar films. This dependence can be measured by experiment and would serve as an additional criterion for determination of the magnetic inhomogeneity types.
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