Some Ways to Modify the Spinwave Mode Spectra of Magnetic Multilayers

摘要

Spin-wave modes in magnetic multilayers are of interest both for basic research and for application for example, in microwave devices. This paper discusses some ways to manipulate the mode-spectra of such multilayers. One way, for example, would be to have reversed magnetization direction in adjacent layers which can be achieved by tailoring the coercive forces of the films in a proper way. The case is discussed where the films are coupled by exchange as well as by the everpresent dipolar interaction. Here the amount of exchange can be tailored by choosing the proper materials or thickness for the nonmagnetic intermediate layers between the magnetic films. These effects have been studied for a couple of Fe sandwiches with intermediate layers of various materials and a short coupling length (less than or equal to 5 A) was found for V and Cr, and a long one (less than or equal to 20 A) for Cu, Ag, Au, and Pd. Taking pinhole effects into account this could be correlated with the different crystal structures but it could also be explained by charge transfer effects considering the electronegativities of these materials. (ERA citation 11:000876)