Synthesis and characterization of Ni1-xZnxFe2O4 spinel ferrites from tailored layered double hydroxide precursors

In this paper, a series of pure Ni1-xZnxFe2O4 (0 <= x <= 1) spinel ferrites have been synthesized successfully using a novel route through calcination of tailored hydrotalcite-like layered double hydroxide molecular precursors of the type [(Ni + Zn)(1-x) - Fey2+Fex3+(OH)(2)](x+)(SO42-)(x/2)center dot mH(2)O at 900 degrees C for 2 h, in which the molar ratio of (Ni2+ + Zn2+)/(Fe2+ + Fe3+) was adjusted to the same value as that in single spinel ferrite itself The physico-chemical characteristics of the LDHs and their resulting calcined products were investigated by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and Mossbauer spectroscopy. The results indicate that calcination of the as-synthesized LDH precursor affords a pure single Ni1-xZnxFe2O4 (0 <= x <= 1) spinel ferrite phase. Moreover, formation of pure ferrites starting from LDHs precursors requires a much lower temperature and shorter time, leading to a lower chance of side-reactions occurring, because all metal cations on the brucite-like layers of LDHs can be uniformly distributed at an atomic level. (c) 2005 Elsevier Ltd. All rights reserved.