Cation Distribution and Magnetic Properties of Gd⁺³-Substituted Ni-Zn Nano-ferrites

A series of Gd⁺³-substituted nanocrystalline Ni-Zn ferrites Ni_1-xZn_xGd_0.1Fe_1.9O₄ (0 ≤ x ≤ 1) are prepared using a low-temperature citrate auto-combustion method. The cation distribution obtained using powder x-ray diffraction demonstrates an increase in hopping length between magnetic and Zn⁺² ions. Cation–oxygen vibrations are identified by FTIR spectra. Effect of Zn⁺² ion on the magnetic properties at room temperature is determined from the magnetic moment measured through a vibrating sample magnetometer. The magnetic moment and saturation magnetization obey Yafet–Kittel type magnetization with the highest saturation magnetization for x = 0.2 (≈ 54 emu/g). The low squareness ratio of the samples (0.25–0.12) confirms the uniaxial anisotropy.