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Magnetodielectric Ni ferrite ceramics with Bi2O3 additive for potential antenna miniaturizations

Published online by Cambridge University Press:  31 January 2011

X.T. Liew ,
K.C. Chan  and
L.B. Kong
L.B. Kong*
Affiliation:
Temasek Laboratories, National University of Singapore, Singapore 119260
*
d) Address all correspondence to this author. e-mail: [email protected]
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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 NiFe1.98O4 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 NiFe1.98O4 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.

Keywords

CeramicDielectric propertiesMagnetic properties
Type
Articles
Information
Journal of Materials Research , Volume 24 , Issue 2 , February 2009 , pp. 324 - 332
Copyright
Copyright © Materials Research Society 2009

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References

REFERENCES

1.Skrivervik, A.K., Zürcher, J.F., Staub, O., Rosig, J.R.: PCS antenna design: The challenge of miniaturization. IEEE Antennas Propagat. Mag. 43, (4)12 (2001)CrossRefGoogle Scholar
2.Mosallaei, H., Sarabandi, K.: Magneto-dielectrics in electromagnetics: Concept and applications. IEEE Trans. Antenn. Propag. 52, (6)1558 (2004)CrossRefGoogle Scholar
3.Buell, K., Mosallaei, H., Sarabandi, K.: A substrate for small patch antennas providing tunable miniaturization factors. IEEE Trans. Microw. Theory Tech. 54, (1)135 (2006)CrossRefGoogle Scholar
4.Colburn, J.S., Rahmat-Samii, Y.: Patch antennas on externally perforated high-dielectric constant substrates. IEEE Trans. Antenn. Propag. 47, (12)1785 (1999)CrossRefGoogle Scholar
5.Mongia, R.K., Ittipiboon, A., Cuhaci, M.: Low profile dielectric resonator antennas using a very high permittivity material. Electron. Lett. 30, (17)1362 (1994)CrossRefGoogle Scholar
6.Kong, L.B., Li, Z.W., Lin, G.Q., Gan, Y.B.: Magneto-dielectric properties of Mg–Cu–Co ferrite ceramics: I. Densification behavior and microstructure development. J. Am. Ceram. Soc. 90, (10)3106 (2007)CrossRefGoogle Scholar
7.Kong, L.B., Li, Z.W., Lin, G.Q., Gan, Y.B.: Magneto-dielectric properties of Mg-Cu-Co ferrite ceramics: II. Electrical, dielectric and magnetic properties. J. Am. Ceram. Soc. 90, (7)2104 (2007)CrossRefGoogle Scholar
8.Kong, L.B., Li, Z.W., Lin, G.Q., Gan, Y.B.: Electrical and magnetic properties of magnesium ferrite ceramics doped with Bi2O3. Acta Mater. 55, (19)6561 (2007)CrossRefGoogle Scholar
9.Verma, A., Dube, D.C.: Processing of nickel–zinc ferrites via the citrate precursor route for high-frequency applications. J. Am. Ceram. Soc. 88, (3)519 (2005)CrossRefGoogle Scholar
10.Drofenik, M., Znidarsic, A., Makovec, D.: Influence of the addition of Bi2O3 on the grain growth and magnetic permeability of MnZn Ferrites. J. Am. Ceram. Soc. 81, (11)2841 (1998)CrossRefGoogle Scholar
11.Murbe, J., Topfer, J.: Ni–Cu–Zn ferrites for low temperature firing: II. Effects of powder morphology and Bi2O3 addition on microstructure and permeability. J. Electroceram. 16, 199 (2006)CrossRefGoogle Scholar
12.Wang, S.F., Wang, Y.R., Yang, T.C.K., Chen, C.F., Lu, C.A., Huang, C.Y.: Densification and magnetic properties of low-fire NiCuZn ferrites. J. Magn. Magn. Mater. 220, 129 (2000)CrossRefGoogle Scholar
13.Ram, S., Krishnan, H., Rai, K.N., Narayan, K.A.: Magnetic and electrical properties of Bi2O3 modified BaFe12O19 hexagonal ferrite. Jpn. J. Appl. Phys. 28, (4)604 (1989)CrossRefGoogle Scholar
14.Mendelson, M.I.: Average grain size in polycrystalline ceramics. J. Am. Ceram. Soc. 52, (8)443 (1969)CrossRefGoogle Scholar
15.Agilent Technologies Theory on Material Measurement. Operational Manual E, Agilent Part No. E4991-90070 Dec. 2005Google Scholar
16.Jorgensen, P.J., Bartlett, R.W.: Liquid-phase sintering of SmCo5. J. Appl. Phys. 44, 2876 (1973)CrossRefGoogle Scholar
17.Lay, K.W.: Grain growth of UO2–Al2O3 in the presence of a liquid phase. J. Am. Ceram. Soc. 51, (7)373 (1968)CrossRefGoogle Scholar
18.Young, A., Hilmas, G., Zhang, S.C., Schwartz, R.W.: Effect of liquid-phase sintering on the breakdown strength of barium titanate. J. Am. Ceram. Soc. 90, (5)1504 (2007)CrossRefGoogle Scholar
19.Miles, P.A., Westphal, W.B., von Hippel, A.: Dielectric spectroscopy of ferromagnetic semiconductors. Rev. Mod. Phys. 29, (3)279 (1957)CrossRefGoogle Scholar
20.Snoek, J.L.: Dispersion and absorption in magnetic ferrites at frequencies above one Mc/s. Physica 14, (4)207 (1948)CrossRefGoogle Scholar
21.Nakamura, T.: Snoek's limit in high-frequency permeability of polycrystalline Ni–Zn, Mg–Zn and Ni–Zn–Cu spinel ferrites. J. Appl. Phys. 88, (1)348 (2000)CrossRefGoogle Scholar
22.Verwell, J.: Magnetic Properties of Materials edited by J. Smith (McGraw-Hill New York 1971)64Google Scholar
23.Johnson, M.T., Visser, E.G.: A coherent model for the complex permeability in polycrystalline ferrites. IEEE Trans. Magn. 26, (5)1987 (1990)CrossRefGoogle Scholar
24.Tsutaoka, T.: Frequency dispersion of complex permeability in Mn–Zn and Ni–Zn spinel ferrites and their composite materials. J. Appl. Phys. 93, (5)2789 (2003)CrossRefGoogle Scholar
25.Globus, A., Duplex, P.: Separation of susceptibility mechanisms for ferrite of low anisotropy. IEEE Trans. Magn. 2, (3)441 (1966)CrossRefGoogle Scholar