Magnetostatic Modes in Disks and Rods

Ferrimagnetic-resonance experiments have been performed using disk- and rod-shaped samples cut from single crystals of a manganese ferrite and of yttrium iron garnet. A multiplicity of absorption maxima were observed which can be identified as magnetostatic modes. The excitation of different sets of modes by rf magnetic field configurations of varying symmetries aids in assigning indices to the modes observed. By far the narrowest lines were observed in thin disks with the steady field normal to the plane of the disk.