Effect of plane polarized light on the domain structure in a Ysub(3)Fesub(5-x)Sisub(x)Osub(12)

The effect of plane polarized monochromatic light on the local distribution of the magnetization M in a Ysub(3)Fesub(5-x)Sisub(x)Osub(12) plate cut along the (110) plane is observed experimentally at 77 K. Light induces a transition from the labyrinth-like Faraday type of domain structure (DS) to a band-like Cotton type DS. Thus the domain magnetization vector M, which is perpendicular to the surface of the plate, is found to be in the plane of the plate. The photoinduced direction of vector M is along the easy magnetization axis which is closest to the direction of the polarization vector of the incident beam Esub(s). The direction of vector Esub(s) with respect to the crystallographic axes also determines the efficiency (time) of the photoinduced alteration of M. It is shown that the Cotton DS may be altered repeatedly in the absence of an external magnetic field merely by optical means. The effect of an external magnetic field on the photoinduced alteration of the DS is investigated