Effect of Nd substitution on structure and magnetic properties of NdxDy3–xFe5O12 garnet powders

The properties of light rare earth Nd substitution for heavy rare earth Dy in Dy3Fe5O12 (DyIG) garnet ferrite have been studied. The NdxDy3–xFe5O12 (x = 0, 0.25, 0.5, 0.75 and 1) (Nd:DyIG) garnet powders were prepared by sol–gel autocombustion followed by heat treatment. The structure and the magnetic properties of the annealed powders were measured with X-ray diffraction (XRD), the Fourier Transform Infrared (FT-IR) and the Physical Properties Measurement System (PPMS) techniques. The experimental results indicate that a single Nd:DyIG garnet phase structure can be obtained after the samples annealed above 800 C. With the Nd substitution content increasing, the average lattice constants of the sample, the a–d super-exchange interaction strengthens and the magnetization of unit cell increase. The maximum saturation magnetization is 13.86 emu/g for x = 1, and coercive force is about 136 Oe, for x = 0.75. The reason of increasing in magnetization with Nd substitution is also discussed.