Local oxygen diffusion induced in Ca-doped yttrium iron garnet films by laser annealing

Local inward and outward oxygen diffusion induced in Ca-doped yttrium iron garnet films by laser annealing in controlled atmospheres is reported for the first time. This allows changing locally and reversibly the concentration of Fe4+ ions, which control the electrical and infrared optical properties of the material. The effects of laser annealing were investigated by measuring in the irradiated regions the optical absorption and the magnetic circular dichroism in the near infrared. The possibility of small scale maskless treatments and the short times involved make this technique interesting for several device applications.