Sj. Zhang et al., EFFECTS OF RAPID RECURRENT ANNEALING ON STRUCTURE AND MAGNETOOPTICAL PROPERTIES OF GARNET-FILMS, Journal of applied physics, 73(10), 1993, pp. 6832-6834
A new method to improve the morphology and the microstructure of sputt
ered bismuth-substituted garnet films for optical storage is discussed
. The method employs a high ramp up rate and recurrent annealing as we
ll as quenching in an air environment, which results in smaller grain
size, smoother surface, and less void volume in the garnet films than
that from a conventional oven annealing. We have discovered that sampl
es prepared with a more recurrent annealing only appeared as a single
garnet phase, and the samples with a less recurrent annealing appeared
as a garnet phase as well as DyFeO3 phase. We observed the microstruc
ture of the annealed films with scanning electron microscopy (SEM). By
applying the new method, the as-deposited films had been successfully
crystallized to the (BiDy)3(FeGa)5O12 garnet phase with the grain siz
e of about 300-400 angstrom. They exhibited excellent magneto-optical
properties with a high coercive force about 1300 Oe and an effective K
err angle of 1.5-degrees. The crystallization process of as-deposited
amorphous films as well as the structure, composition, and magnetic an
d magneto-optical properties of the crystallized garnet films were exa
mined.