Magnetic and FTIR studies of Bi xY 3− xFe 5O 12 ( x = 0, 1, 2) powders prepared by the metal organic decomposition method

Abstract

The crystallization process of bismuth substituted yttrium iron garnet (Bi x Y 3− x Fe 5O 12; x = 0, 1, 2) powder prepared by the metal-organic decomposition method has been studied with various sintering temperatures. The pure garnet phase was observed for the x = 1 powder at 900 °C sintering temperature, whereas the x = 0, 2 powder showed secondary phases. The x = 0 powder showed a similar crystallization process to that of the solid state reaction method. For the x =1, 2 powders, it is proposed that the lowering of the crystallization temperature is due to the lowered stability of the intermediate phase. The infrared spectroscopy and magnetic properties were also investigated. The pure garnet phase showed three absorption bands located at 563, 598, 655 cm −1 that shifted to 555, 588, 639 cm −1 along with an increase of bismuth concentration. The maximum values of saturation and remanence magnetization and the minimum value of coercivity were observed for the x = 1 powder sintered at 900 °C, which were 20.8 emu/g, 2.67 emu/g, and 31.9 Oe, respectively.