Magnetic and magneto-optic properties of rapid thermally crystallized garnet films (invited)

A new technique to improve the morphology of sputter-deposited bismuth garnet films for optical storage is discussed. This technique employs high ramp-up rate annealing in a nitrogen atmosphere, which leads to a smaller grain size and smoother surface than a conventional oven annealing or in situ crystallization process during film growth. By utilizing this technique, the films can be successfully crystallized to the grain size of about 200-300 Å, and a high coercivity (≳kOe). Multilayer films of garnets with other additions such as Cr and SiOx are also discussed. These multilayer films can provide better morphology and high coercivity.