Abstract:

Ferrite compound Co_0:6Zn_0:4NixFe_2-xO₄ was synthesized by solid state reaction. The structure and performance of Co_0:6Zn_0:4Ni_xFe_2-xO₄ compounds were studied by MÄossbauer spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and infrared radiant tester. MÄossbauer spectroscopy and XPS analysis show the valence states and distribution of cations in Co_0:6Zn_0:4Ni_xFe_2-xO₄. Zn²⁺ has invariably shown preference for the tetrahedral sites, and Ni²⁺ has the preference for the octahedral sites. The occupancy of Fe³⁺ linearly increases on the tetrahedral sites, and sharply decreases on the octahedral sites with increasing x, owing to its gradual replacement by Ni²⁺ on the octahedral sites. It indicates that due to the occupation of octahedral sites by the majority of Ni²⁺, Fe³⁺ decreasingly migrated from the octahedral sites to the tetrahedral sites and substituted Co³⁺ sites, which made the number of Co³⁺ in the tetrahedral sites decreasing. According to the measurement results of XRD and the infrared radiant tester analysis, the lattice parameter and infrared radiance have shown a nonlinear variation, exhibiting the infrared average radiance of 0.92 in the 8-14 μm waveband, and the results demonstrate that these Co-Zn-Ni spinel ferrites have potential for application in a wide range of infrared heating and drying materials.

Key words: Infrared radiance, Mossbauer spectroscopy, NiO, Spinel ferrites