Modes of Resonance Absorptions of Magnetostatic Waves in Axially Magnetized YIG Rods

The magnetostatic resonance absorptions for an axially magnetized single crystal of YIG rod, [110] oriented, are observed in a waveguide and a cavity at 9.45 GHz. For the applied magnetic field ranging from 2800 to 3400 Oe resonance absorptions due to the dominant and third modes are observed but the second mode is not excited. The separation of these modes is conducted by comparing the transmitted power with the reflected microwave power pattern. For the dominant and third modes the relations between the field deviation, ΔH, from the cutoff field and the standing wave number n for each absorption are in good agreement between the theoretical and experimental values in a wide range of dc magnetic field. When the entire rod is inserted into the center of a waveguide or a cavity only the absorptions due to modes associated with an odd number, n, are observed for both dominant and third modes