Single Crystal Growth and Magneto-Optical Properties of Bi, Al-Substituted Magnetic Garnets

Al was substituted for the iron in the garnet in Bi-substituted magnetic garnet single crystals in an attempt to reduce saturation magnetization and absorption loss. The Bi-, Al-substituted magnetic garnet showed an approximately 20 percent drop in absorption in the neighborhood of 0.8 ¿m wavelength with no loss in figure of merit because ¿F decreased also. Faraday rotation angle measurements established that the saturation magnetism of the Al-substituted crystal was less than half that of the non-substituted crystal. It was also found that as the amount of Bi substituted increases, the compensating temperature (Tcomp) decreases, while Tcomp increases as the amount of Al substituted is increased. The results showed conclusively that Bi-, Al-substituted garnet is a material with superb magneto-optical properties, with low saturation magnetization and low absorption loss.