Spin wave spectra in layered composite materials are computed by means of a transfer matrix method with evidence for existence of numerous frequency gaps. Essential properties of these spectra are successfully explained within the framework of approximate models of independent films or an effective medium, according to the strength (strong and weak, respectively) of the magnetization and exchange contrasts; this includes an evidence of the existence of resonance states, for which both materials are simultaneously excited. (C) 2001 Elsevier Science B.V. All rights reserved. [References: 16]
展开▼
