Magnetic and dielectric properties in the UHF frequency band of half-dense Ni-Zn-Co ferrites ceramics with Fe-excess and Fe-deficiency - Université de Bretagne Occidentale Access content directly
Journal Articles Journal of Magnetism and Magnetic Materials Year : 2018

Magnetic and dielectric properties in the UHF frequency band of half-dense Ni-Zn-Co ferrites ceramics with Fe-excess and Fe-deficiency

Abstract

This work investigates electromagnetic properties of half-dense ceramics with compositions Ni 0.5 Zn 0.3 Co 0.2 Fe y O 4-d where y = 1.98 (Iron deficient, noted ID) or y = 2.3 (Iron in excess, noted IE). IE and ID materials are obtained by chemical coprecipitation route. The obtained nano-sized powders are pressed and annealed at two temperatures (800 °C, 900 °C), so has to obtain half-massive ceramics. Ferrous and ferric ions coexist in the crystalline structures, but the former in a less extend for ID ferrite. The concomitant influences of Fe 2+ and Fe 3+ on the dielectric and magnetic losses (e 00 /e 0 and m 00 /m 0 , respectively) are considered at frequency up to 6 GHz. The permeability dispersion changes from relaxation-like to resonance-like with the decrease in ferrous ions. In reason of the relaxing-like behavior of Fe 2+ , and because of a relatively high amount in Fe 2+ , IE sample shows lower total losses (magnetic and dielectric) than ID sample. These conclusions applied for T A = 900 °C. At frequencies above 700 MHz, the total loss values (IE and ID samples) are prohibitive for antenna downsizing whatever is the firing temperature value (800 °C and 900 °C). Whereas at frequencies below 700 MHz Ni 0.5 Zn 0.3 Co 0.2 Fe 2.3 O 4+d may leads to better antenna performances than Ni 0.5 Zn 0.3 Co 0.2 Fe 1.98 O 4-d .
No file

Dates and versions

Identifiers

Cite

Jean-Luc Mattei, David Souriou, Alexis Chevalier. Magnetic and dielectric properties in the UHF frequency band of half-dense Ni-Zn-Co ferrites ceramics with Fe-excess and Fe-deficiency. Journal of Magnetism and Magnetic Materials, 2018, 447, pp.9 - 14. ⟨10.1016/j.jmmm.2017.09.030⟩. ⟨hal-01690608⟩
131 View
0 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More