Magnetic aftereffects in Si-doped YIG

Magnetic aftereffect processes in yttrium iron garnet with silicon substitutions are analyzed by means of magnetic disaccommodation techniques. We have recorded the time evolution of the initial magnetic permeability after sample demagnetization for polycrystalline specimens with nominal composition Y/sub 3/Fe/sub 5-x/Si/sub x/O/sub 12/ (0/spl les/x/spl les/1) in the temperature range from 80 K to 500 K. We have found that silicon substitutions give rise to new relaxation and frequency dependent accommodation processes at high and low temperatures, respectively. The origins of both types of processes are finally discussed.