Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-28T00:53:21.626Z Has data issue: false hasContentIssue false
  • English
  • Français

Crystal structure and microwave dielectric properties of low temperature sintered MgO ceramic with LiF addition

Published online by Cambridge University Press:  06 February 2012

Akinori Kan ,
Hirotaka Ogawa  and
Tohru Moriyama
Akinori Kan*
Affiliation:
Department of Transportation Engineering, Meijo University, Nagoya 4688502, Japan
Hirotaka Ogawa
Affiliation:
Department of Transportation Engineering, Meijo University, Nagoya 4688502, Japan
Tohru Moriyama
Affiliation:
Department of Transportation Engineering, Meijo University, Nagoya 4688502, Japan
*
a)Address all correspondence to this author. e-mail: akan@meijo-u.ac.jp
Get access

Abstract

The (1−x)MgO–xLiF ceramics (x = 0.02–0.08) were successfully sintered when the ceramics were sintered at 950 °C for 4 h in covered crucible. From the crystal structure analysis, it was found that a small amount of Li+ cation occupied Mg2+ site in MgO ceramic; the formation of oxygen vacancy induced by Li substitution for Mg was suggested by the evaluation of the bulk conductivity and the calculation of density of state (DOS) for the (Mg13O43)−60 and (Mg11Li2O42)−58 cluster models. As for the microwave dielectric properties of the (1−x)MgO–xLiF ceramics, the dielectric constant εr and the temperature coefficient of resonant frequency values of the ceramic were independent of the lithium fluoride (LiF) content, and these values were approximately 9.5 and −62 ppm/°C. On the other hand, the quality factor values strongly depended on the LiF content. As a result, the highest value of 282,230 GHz was obtained at x = 0.04. From these results, it is determined that the LiF addition is effective in reducing the sintering temperature of MgO without any detrimental effect on the microwave dielectric properties of MgO ceramics.

Keywords

dielectric propertiesceramicMg
Type
Articles
Information
Journal of Materials Research , Volume 27 , Issue 6 , 28 March 2012 , pp. 915 - 921
Copyright
Copyright © Materials Research Society 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Byeon, T., Park, H.S., Shin, H., Yoon, S.O., and Oh, C.Y.: Thermal expansion and dielectric properties of CaO-ZnO-B2O3-SiO2 glass-added Al2O3 composites for LTCC applications. J. Korean Ceram. Soc. 47(4), 325 (2010).CrossRefGoogle Scholar
2.Kim, K.S., Jang, H.S., Shin, H., Kim, I.T., Shin, H., Yong, H., and Yoon, S.O.: Various filler added CaO-Al2O3-SiO2 glass composites for LTCC substrate applications. J. Korean Ceram. Soc. 46(3), 323 (2009).Google Scholar
3.Eberstein, M., Reinsch, S., Mueller, R., Deubener, J., and Schiller, W.A.: Sintering of glass matrix composites with small rigid inclusions. J. Eur. Ceram. Soc. 29(12), 2469 (2009).CrossRefGoogle Scholar
4.Dai, S.X, Haung, R.F., and Wilcox, D.L.: Use of titanates to achieve a temperature-stable low-temperature co-fired ceramic dielectric for wireless applications. J. Am. Ceram. Soc. 85(4), 828 (2002).CrossRefGoogle Scholar
5.Shin, H.K., Shin, H., Cho, S.Y., and Hong, K.S.: Phase evolution and dielectric properties of MgTiO3-CaTiO3-based ceramic sintered with lithium borosilicate glass for application to low temperature co-fired ceramics. J. Am. Ceram. Soc. 88(9), 2461 (2005).Google Scholar
6.Chang, M.W., Lyoo, S.H., Choo, H.S., and Lee, J.M.: Properties of glasses based on the CaO-MgO-SiO2 system for low-temperature co-fired ceramic. Ceram. Int. 35(6), 2513 (2009).CrossRefGoogle Scholar
7.Choi, I.J. and Cho, Y.S.: Effects of various oxide fillers on physical and dielectric properties of calcium aluminoborosilicate-based dielectrics. J. Electroceram. 23(2–4), 185 (2009).Google Scholar
8.Carnall, E. Jr.: The densification of MgO in the presence of liquid phase. Mater. Res. Bull. 2, 1075 (1967).CrossRefGoogle Scholar
9.Hakki, B.W. and Coleman, P.D.: A dielectric resonator method of measuring inductive capacities in the millimeter range. IRE Trans. Microwave Theory Tech. 8, 402 (1960).Google Scholar
10.Kobayashi, Y. and Katoh, M.: Microwave measurement of dielectric properties of low-loss materials by dielectric resonator method. IEEE Trans. Microwave Theory Tech. 33, 586 (1985).CrossRefGoogle Scholar
11.Adachi, H., Tsukada, M., and Satoko, C.: Discrete variational Xα cluster calculations. I. Application to metal clusters. J. Phys. Soc. Jpn. 45(3), 875 (1978).Google Scholar
12.Tsukada, M., Satoko, C., and Adachi, H.: Surface electronic structure of rutile (TiO2) by the DV-Xα cluster calculation. J. Phys. Soc. Jpn. 44(3), 1043 (1978).CrossRefGoogle Scholar
13.Itzhak, D., Kornblit, L., and Grill, A.: Electrical conductivity of hot-pressed magnesia: Effect of the addition of LiF. Mater. Sci. Eng. 48, 261 (1981).Google Scholar
14.Andersen, A.G. and Norby, T.: Liquid phases in Li:MgO as studied by thermoanalytical methods, electron microscopy, and electrical conductivity measurements. Catal. Today 6, 575 (1990).CrossRefGoogle Scholar
15.Shannon, R.D.: Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Cryst. A32, 751 (1976).Google Scholar
16.Kröger, F.A. and Vink, H.J.: Relations between concentrations of imperfections in crystalline solids. Solid State Phys. 3, 307 (1956).CrossRefGoogle Scholar
17.Reiling, G.H. and Hensley, E.B.: Fundamental optical absorption in magnesium oxide. Phys. Rev. 112(4), 1106 (1958).Google Scholar