Magneto-optical imaging using a garnet indicator film prepared on glass substrates

We observed the magnetic domains of a magnetic card by using the bismuth-substituted yttrium iron garnet (Bi-YIG; Bi(1)Y(2)Fe(5)O(12)) thin films as the indicator films. The magnetic domains' dependence on the preparation conditions of the garnet thin film crystals was visualized by using a magneto-optical microscope. Garnet thin films were fabricated on glass substrates using a metal-organic decomposition method (MOD). We found that bigger Faraday rotation was measured in the better crystallized indicator films. Polycrystalline Bi-YIG thin films were successfully obtained for the annealing temperature of 700 degrees C and an annealing time of 1 h. The thickness of the film was about 47 nm for a single coating during the MOD process. The Faraday-rotation angle of the films was estimated as -2.47 degrees/mu m and the angle was comparable to other synthesis methods, such as the sol-gel and the RF-magnetron sputtering. Using these indicator films, we could image the magnetic domains of magnetic materials. (C) 2010 Elsevier B.V. All rights reserved.