Structural, Infrared and Magnetic Properties of Nanosized Ni(x)Zn1-xFe2O4 Powders Synthesized by Sol-Gel Technique.

Ni-Zn ferrites Ni(x)Zn1-xFe2O4 (x = 0.2, 0.4, 0.5, 0.6, 0.8) powders were synthesized by sol-gel technique. Structural, infrared and magnetic properties of samples were investigated. Spinel structural characteristics are shown by XRD spectra and the morphologies observed by atomic force microscopy demonstrate the samples are in nano-range. For all the samples, FTIR spectra exhibit obvious v1 infrared absorbing bands, in the range 500-600 cm-1, corresponding to intrinsic stretching vibrations of the metal ions at the tetrahedral site (Td), Mtetra <--> O. Furthermore, the central position of v1 band is tending to shift to larger wave numbers with the increasing Ni contents in the samples. For the samples Ni(x)Zn1-xFe2O4 (x = 0.2, 0.4), the v2 infrared absorbing bands, in the range 450-385 cm(-1), corresponding to stretching vibrations of the metal ions at the octahedral-metal stretching (Oh), Mocta <--> O, were also observed. However, for samples Ni(x)Zn1-xFe2O4 with higher Ni content (x = 0.5, 0.6, 0.8), the v2 infrared absorbing bands were obscure. The magnetic hysteretic loops at room temperature obtained from vibration samples magnetometer reveal the soft magnetism of the samples. The sample with lowest Ni content, Ni0.2Zn0.8Fe2O4, presents much higher saturation field than the other samples. The coercive field rises with increased Ni content, which is ascribed to the increased magnetocrystalline anisotropy constant with Ni content.