Please use this identifier to cite or link to this item:
|Title:||Magnetodielectric Ni ferrite ceramics with Bi2O3 additive for potential antenna miniaturizations||Authors:||Liew, X.T.
|Issue Date:||Feb-2009||Citation:||Liew, X.T., Chan, K.C., Kong, L.B. (2009-02). Magnetodielectric Ni ferrite ceramics with Bi2O3 additive for potential antenna miniaturizations. Journal of Materials Research 24 (2) : 324-332. ScholarBank@NUS Repository. https://doi.org/10.1557/jmr.2009.0057||Abstract:||This paper reports on the preparation and characterization of nickel ferrite (NiFe1.98O4) ceramics doped with Bi2O3 as sintering aid. Focus has been on the effects of concentration of Bi2O3 and sintering temperature on the densification, grain growth, dielectric, and magnetic properties of the NiFe1.98 O4 ceramics, with an aim at developing magnetodielectric properties, with almost equal real permeability and permittivity, as well as sufficiently low magnetic and dielectric loss tangents, over 3 to 30 MHz (high frequency or HF band). X-ray diffraction results indicated that there is no obvious reaction between NiFe1.98O4 and Bi2O3, at Bi2O3 levels of up to 7 wt% and temperatures up to 1150 °C. The addition of Bi2O3 facilitated a liquid phase sintering mechanism for the densification of NiFe1.9804 ceramics. The addition of Bi2O3 not only improved the densification but also promoted the grain growth of NiFe1.98O4 ceramics. To achieve sufficiently low dielectric loss tangent, the concentration of Bi2O3 should not be less than 5 wt%. The low dielectric loss tangents of the samples doped with high concentrations of Bi2O3 can be attributed to the full densification of the ceramics. Magnetic properties of the NiFe1.98O4 ceramics, as a function of sintering temperature and Bi2O3 concentration, can be qualitatively explained by the Globus model. Promising magnetodielectric properties have been obtained in the sample doped with 5% Bi2O3 and sintered at 1050 °C for 2 h. The sample has almost equal values of permeability and permittivity of ∼12, together with low dielectric and magnetic loss tangents, over 3 to 30 MHz. This material might be useful for the miniaturization of HF (3 to 30 MHz) antennas. © 2009 Materials Research Society.||Source Title:||Journal of Materials Research||URI:||http://scholarbank.nus.edu.sg/handle/10635/115802||ISSN:||08842914||DOI:||10.1557/jmr.2009.0057|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Jan 24, 2021
WEB OF SCIENCETM
checked on Jan 15, 2021
checked on Jan 16, 2021
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.