Switching speed of GdIG crystals near the compensation temperature

Measurements of the switching speed in thin single-crystal wafers of gadolinium iron garnet are described. Pulsed magnetic fields down to 10-ns duration are applied, and the resulting change in the magnetic state is detected optically by the Faraday effect. Data are taken as a function of temperature near the compensation point. The results show interesting temperature and dynamic effects in the switching threshold and switching speed. Many of the observed effects can be accounted for by appropriate models. Most interesting and unexpected is that the wall damping coefficient appears to be an order of magnitude lower than in YIG. The cause for this is not understood. One practical consequence is that the switching power is very low. This may be advantageous in some device applications, even though the coercivity near the compensation temperature becomes very high.