Spin-Wave Resonance in Multilayer Films (One-Dimensional Magnon Crystals). Identification Rules

The characteristic modification of the spectrum of the exchange spin waves has been revealed in ferromagnet/ferromagnet multilayer films with a thickness of N(d(1) + d(2)) by the spin-wave resonance method. This modification is due to the first bandgap at the wavenumber k(b) = pi/(d(1) + d(2)) of a magnon crystal, which is formed by one-dimensional modulation of the magnetization. It has been shown that the transformation of the multilayer film with thermal annealing to the film of a single-phase alloy is accompanied by the disappearance of this modification of the spectrum. DOI: 10.1134/S0021364011160077