Investigation of Magnetic Anisotropy and Spin Wave Modes in Transition Metal Multilayers: Technical Progress Report for the Period August 1986 Through July 1987

摘要

The magnetic properties of compositionally modulated structures known as superlattices or multilayers are of considerable interest because of their application to magnetic recording technology and because of the insight provided into the fundamental nature of magnetism. Anisotropic properties are of vital import in developing stable, well defined, high density magnetic domains in both flux and optically detected magnetic recording media. Spin wave investigations, on the other hand, provide insight into the fundamental nature of surface spin states and interior spin dynamics. Measurements on CuNi and MoNi indicate a very large degree of magnetic anisotropy, which seems to be frequently dependent. The sources of the anisotropy have not been fully explained and the reason for the frequency dependence remains unknown. The FMR measurements on these systems all show definite structure in the perpendicular spectra, but spin wave analysis of this structure has not been reported. Recent FMR linewidth measurements made on MoNi by the P.I., indicate that the lineshape structure is due to spinwave modes. It is reasonable to assume that the source of the anisotropy, its frequency dependence and the spin wave modes observed by FMR are intimately connected. (ERA citation 12:032292)