Formation enthalpy and magnetic properties of Bi-YIG powders

The formation enthalpy and magnetic properties of bismuth-doped yttrium iron garnet powders were investigated. The formation enthalpy and the crystallization temperature both decreased with increasing bismuth substitution for BixY3−xFe5O12 (0.25 ≦ x ≦ 1.25) powders prepared by the coprecipitation process. Bi substitution for Y can significantly reduce crystallization temperature for bismuth-doped yttrium iron garnet powders, and the magnetic properties (saturation magnetization, remanence, and coercive force) are independent of Bi substitution amounts. The average particle size has been determined by the specific surface area. As Bi substitution for Y increased, the average particle size also increased, while the specific surface area decreased.