Synthesis of nickel–zinc–yttrium ferrites: Structural elucidation and dielectric behavior evaluation

Novel Ni0.6Zn0.4Y2xFe2−2xO4 soft spinel ferrites were prepared via double sintering ceramic route. The influence of Y3+ cations on structural, morphological, electrical and dielectric properties was investigated. X-ray diffraction (XRD) confirmed the formation of single phase spinel structure for 0≤x≤0.06 and thereafter a small peak of orthorhombic phase (FeYO3) appeared for x>0.06. The incorporation of yttrium altered the lattice constant. The variation in lattice constant with respect to the Y3+ contents was non-linear. The variation of lattice constant may be attributed to larger ionic radius of Y3+ as compare to Fe3+ cations and solubility limit of substituted cations. Fourier transform infrared (FTIR) spectra showed two strong absorption bands around 600 cm−1 and 400 cm−1 which confirmed the spinel structure. The dc electrical resistivity was found to increase from 5.67×105 to 8.48×108 Ω cm with the increased Y3+ contents. The dielectric constant and dielectric loss tangent were significantly impeded by increasing the yttrium contents. The optimized electrical resistivity and reduced dielectric parameters suggest the possible use of these ferrites in the fabrication of microwave devices.