Structure and Microwave Absorption Properties of Rare Earth Gd3+ Doped Cobalt Ferrite

When the cetyltrimethylammonium bromide (CTAB) was used as surfactant, C4H6CoO4 center dot 6H(2)O and FeCl3 center dot 6H(2)O as starting material, the crystallization temperature was 180 degrees C, the crystallization time lasted 8 h, and the pH was 11, cobalt ferrite nanoparticles were prepared by a hydrothermal method. The doped rare earth element Gd3+ was used to control the structure and absorbing properties of cobalt ferrite, and at the same time we explored the impact of rare earth element amount on the microstructure and microwave absorbing properties of nano cobalt ferrite. The structure and absorbing properties of cobalt ferrite were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), transmission electron microscopy (TEM) and vector network analyzer (VNA). It is found that during the period of the preparation of cobalt ferrite, the doping of rare earth element Gd3+ has a great influence on grain size, morphology and absorbing properties. The results show that when the doping amount of Gd3+ x <= 0.025, the grain size of cobalt ferrite becomes smaller, while the lattice constant gradually increases and the shape of the particles becomes irregular quadrangles with the increase of doping amount, which indicates that rare earth element Gd3+ can make the particles smaller. When the solid solubility of the Gd3+ in the cobalt ferrite reaches the limit, Gd(OH)(3) impurity is generated, and the cobalt ferrite grain size is increased when the Gd3+ doping amount x>0.025. The absorbing reflectivity of cobalt ferrite reaches the minimum values of -14.9 dB when the doping amount of Gd3+ is 0.025.