Oscillatory buckling mode in thin-film nucleation
The authors point out that this films of ferromagnetic materials have a number of properties which can affect their magnetization: material length, sample dimension and a long-range spin-interaction. Thus results in such materials having the possibility of existing in different states. The authors analyze the conditions for four such states. This theory, they feel, supersedes the Aharoni theory which only allows of three states: In the analysis, it is shown that the four states depend basically on the film thickness. The four regimes are, in order of measuring thickness. (1) Coherent rotation which involves surface charges. (2) Non-oscillatory buckling, a regime existing without surface charges. (3) Oscillatory buckling which is associated with a competition between volume charges and exchange energy. (4) Curling where there is avoid once of both surface and volume charges. Using variatonal methods, the authors analyze the conditions under which the four states exist and evaluate the upper and lower bounds for the boundaries between the states. The analysis is long involving several lemmas, and consequently will not be treated here.
scientific article; zbMATH DE number 5073819