Structure and Magnetic Properties of Sputtered Bi₂DyFe₅O₁₂ Films

The effects of the annealing temperature and time on the structure and magnetic properties of the sputtered BiDy-iron garnet films were investigated. X-ray diffraction analysis shows that the as-sputtered films are amorphous. After annealing at about 550°C, amorphous films crystallize into the garnet phase and an unknown phase. The intensity of the unknown phase decreases with increasing annealing temperature and time and vanishes at 650°C for 30min. It is found that the unknown phase has a large influence on the half-width of the (420) x-ray diffraction peak. The as-sputtered films have a very small magnetization of about 1 emu/g at room temperature. When films are annealed above 570°C, the magnetization increases rapidly with increasing annealing temperature and time.