PHOTOINDUCED DISACCOMMODATION IN OXYGEN-DEFICIENT YTTRIUM-IRON-GARNET

When a single crystal of yttrium iron garnet, YIG (Ga:0.0625) with nat ive defect of oxygen is exposed to optical light at 77 K, disaccommoda tion of magnetic permeability (DA) ir. observed to occur around 140 K and 210 K, as reported earlier. Furthermore, the third DA peak indepen dent of illumination is found around room temperature in some samples, when the sample temperature is raised up to 400 K. The mechanism of t hese DA peaks and photoinduced irreversible decrease of initial permea bility (PME) is discussed, qualitatively, in a systematic way.