B. Ghate—contributing editor
Processing of Nickel–Zinc Ferrites Via the Citrate Precursor Route for High-Frequency Applications
Article first published online: 24 FEB 2005
Journal of the American Ceramic Society
Volume 88, Issue 3, pages 519–523, March 2005
How to Cite
Verma, A. and Dube, D. C. (2005), Processing of Nickel–Zinc Ferrites Via the Citrate Precursor Route for High-Frequency Applications. Journal of the American Ceramic Society, 88: 519–523. doi: 10.1111/j.1551-2916.2005.00098.x
- Issue published online: 24 FEB 2005
- Article first published online: 24 FEB 2005
- Manuscript No. 186947. Received May 29, 2002; approved March 9, 2004.
Nickel–zinc ferrites of various compositions, Ni1−xZnxFe2O4 where x=0.2, 0.4, 0.5, and 0.6 investigated in the present work, have been prepared by the citrate precursor method. The complex permittivity (∈′−j∈″) and permeability (μ′−jμ″) of the ferrites were measured at X-band (8–12 GHz) microwave frequencies. The dielectric constants or the real part of permittivity, ∈′, are observed to lie in the range 5.46–8.95 for ferrites sintered at 1200°C, while those sintered at 1300°C exhibit relatively higher dielectric constants. The permittivity loss, tan δ∈ (=∈″/∈′), is observed to be of the order of 10−2–10−3, depending upon the composition and sintering temperature of the ferrite. These losses are lower by at least one to two orders of magnitude compared with those normally reported for ferrites processed by the conventional ceramic method. The presently studied ferrites also exhibit high values of DC-resistivity, 107–1011Ω·cm. The low dielectric losses and high resistivity can be co related to small grain size and better compositional stoichiometry obtained as a result of processing via the citrate route. Magnetic properties such as the Curie temperature, saturation magnetization, initial permeability, and B–H hysteresis parameters of the compositions with x=0.5 and 0.6 are also given.