Annealing behavior of deuterium implanted garnet films

The total implantation-induced anisotropy field change and the portion of it which is attributable to magnetostriction were measured on deuterium implanted films which were annealed up to 800°C. Results for three films, the first of which was coated with SiO2before implantation, the second of which was coated afterwards, and the third of which was left uncoated are compared. On the uncoated film, there is a rapid decrease in the anisotropy field change at low annealing temperatures, which is presumably caused by the desorption of deuterium. Overcoating with SiO2prevents desorption up to 450°C. Even after the deuterium desorbs from the garnet as a result of anneals up to 800°C. magnetostrictive effects account for only 1/3 of the total anisotropy field change. By comparison, it was found that more than 2/3 of the anisotropy field change in oxygen implanted films can be attributed to magnetostrictive effects. Finally, the resonance signal from the uncoated film was considerably weaker than that in the film coated before implantation, even though the strain profiles on both films are similar, suggesting that implantation through an overcoat has a beneficial effect on the magnetic properties of the implanted layer.