Microwave magnetic resonance and absorption in holmium single crystals
Snyder, Carey Hamilton
Donoho, Paul L.
Master of Arts
Field dependent microwave absorption has been observed in single crystal basal plane platelets of holmium in the range 35° K to 80° K. The rf field was aligned parallel to an easy "b" axis with the dc field at an angle of 0°, 30°, 60°, or 90° to the rf field. No sharp resonances were observed, nor were any peaks of the sort reported by Bagguley and Liesegang, and by Stanford. The failure to observe these peaks is believed to arise from the fact that the sample was cemented down both in the center and on the edges. Stanford observed that this diminished or destroyed these peaks. Changes in absorption occurring at the onset of changes in the magnetic structure were detected. Furthermore, it was observed that with the rf field along an easy direction, the absorption varied as a function of the angle between the rf and dc fields. This indicates that spin wave processes are responsible for the absorption rather than magnetic domain and phase effects as supposed by Stanford.