Resonant microwave absorption in Ising systems: holmium-yttrium iron garnets
Lagutin A. S., Popov A. I.
Dynamic properties of the magnetic system of a Ho0 4 Y2.e FesO 12 single crystal have been studied in strong magnetic fields. In addition to the absorption lines associated with magnetic phase transitions which are familiar from static measurements, there is a large number of resonances far from these points. These resonances occur in fields below the exchange field and also in fields well above the exchange field. The results are interpreted on the basis of a model of an Ising ordering of holmium ions.