Photoinduced disaccommodation of magnetic permeability in yttrium iron garnet (abstract)

After illuminating a single crystal of yttrium iron garnet grown by a modified floating zone method at 77 K, the complex permeability was measured from 77 to 300 K under low alternating field. As well as the decreasing of permeability and the appearance of a peak in μ″‐T curve, disaccommodation (DA) or the change of permeability with time was found to be induced around 140 and 210 K. As the result of the superposition of disaccommodation, the peak in the μ″‐T curve is observed to be divided. These photoinduced magnetic effects cannot be attributed to a single origin, for only photoinduced DA disappears in the process of warming. The origins are discussed and a model is proposed, taking account of the mobility of oxygen vacancy depending on the charge state and the photoexcited electron.