Influence of ZnO and Nb₂O₅ Additions on Sintering Behavior and Microwave Dielectric Properties of (Mg_0.95Ca_0.05 )TiO₃ Ceramics

Abstract:

The influence of ZnO and Nb₂O₅ additions on the sinterability, microstructure and microwave dielectric properties of (Mg_0.95Ca_0.05)TiO₃ (abbreviated as 95MCT hereafter) ceramic is investigated. XRD patterns indicate that MgTi₂O₅ secondary phase can be effectively suppressed by ZnO and Nb₂O₅ additions, which is beneficial for improving the microwave dielectric properties. Appropriate amount of Nb₂O₅ addition can effectively improve the Qf value of 95MCT ceramic, which is suggested to be ascribed to the reduced oxygen vacancies. When the ZnO: Nb₂O₅ mole ratio is 1.5 and the co-doping content is 0.25wt%, the optimal microwave dielectric properties can be obtained Qf=72730GHz(6.8GHz), ε_r=20.29 and τ_f=-6.84ppm/°C and the sintering temperature of 95MCT is lowered from 1400°C to 1320°C.

• Periodical: Key Engineering Materials (Volumes 512-515)
• Pages: 1184-1188
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.512-515.1184
• Online since: June 2012
• Authors: Chun Ya Luo, Ming Zhe Hu, Quian Huang, Yang Fu, Hao Shuang Gu
• Keywords: Addition, Microwave Dielectric Ceramics, Oxygen Vacancy, Secondary Phase

References

[1] R.C. Kell, A.C. Greenham and G.C.E. Olds, High-Permittivity Temperature-Stable Ceramic Dielectrics with Low Microwave Loss, J. Am. Ceram. Soc. 56(1973) 352-354.

DOI: 10.1111/j.1151-2916.1973.tb12684.x

[2] C.L. Huang, J.T. Tasi and Y.B. Chen, Dielectric properties of (1-y)Ca1-xLa2x/3TiO3-y(Li,Nd)1/2TiO3 ceramic system at microwave frequency, Mater. Res. Bull. 36(2001) 547-556.

DOI: 10.1016/s0025-5408(01)00528-1

[3] H.T. Kim, J.D. Byun and Y. Kim, Microstructure and Microwave Dielectric Properties of Modified Zinc Titanates, Mater. Res. Bull. 33(1998) 963-973.

DOI: 10.1016/s0025-5408(98)00056-7

[4] M.L. Hsieh, L.S. Chen, S.M. Wang, et al, Low-temperature sintering of microwave dielectrics (Zn, Mg)TiO3, Jpn. J. Appl. Phys. 44(2005) 5045-5048.

[5] H.T. Kim, S. Nahm and J.D. Byun, Low-Fired (Zn, Mg)TiO3 Microwave Dielectrics, J. Am. Ceram. Soc. 82(1999) 3476-3480.

DOI: 10.1111/j.1151-2916.1999.tb02268.x

[6] X.H. Zhou, Y. Yuan, L.C. Xiang, et al, Synthesis of MgTiO3 by solid state reaction and characteristics with addition, J. Mater. Sci. 42(2007) 6628-6632.

DOI: 10.1007/s10853-007-1510-4

[7] W. Wersing, Electronic Ceramics, Elsevier, London, (1991)

[8] C.L. Huang, J.L. Hou, C.L. Pan, et al, Effect of ZnO additive on sintering behavior and microwave dielectric properties of 0.95MgTiO3–0.05CaTiO3 ceramics, J. Alloys Compd. 450(2008) 359-363.

DOI: 10.1016/j.jallcom.2006.10.132

[9] C.L. Huang, C.H. Shen, C.L. Pan, Characterization and dielectric behavior of V2O5-doped MgTiO3–CaTiO3 ceramic system at microwave frequency, Mater. Sci. Eng. B. 145 (2007) 91-96.

DOI: 10.1016/j.mseb.2007.10.016

[10] B.W. Hakki, P.D. Coleman, IEEE Trans. Microwave Theory Tech. 8(1960) 402.

[11] M.A. Sanoj, Manoj Raama Varma, Sinterability and microwave dielectric properties of 0.95MgTiO3–0.05CaTiO3–glass ceramic composites, J. Alloys Compd. 477 (2009) 565-569.

DOI: 10.1016/j.jallcom.2008.10.069

[12] C.H. Shen, C.L. Huang, L.M. Lin, et al, Characterization and dielectric behavior of V2O5-doped 0.9Mg0.95Co0.05TiO3-0.1Ca0.6La0.8/3TiO3 ceramic system at microwave frequency, J. Alloys Compd. 489(2010) 170-174.

DOI: 10.1016/j.jallcom.2009.09.045

[13] C.L. Huang, M.H. Weng and C. Wu, Improved high q value of MgTiO3-CaTiO3 microwave dielectric ceramics at low sintering temperature, Mater. Res. Bull. 36(2001) 2741-2750.

DOI: 10.1016/s0025-5408(01)00752-8

[14] R.M. Germen, Liquid phase sintering, Plenum Publishing, New York, (1985)

[15] V.A. Izhevskyi, A.H.A. Bressiani and J.C. Bressiani, Effect of Liquid Phase Sintering on Microstructure and Mechanical Properties of Yb2O3-AlN Containing SiC-Based Ceramics, J. Am. Ceram. Soc. 88(5) (2005) 1115-1121.

DOI: 10.1111/j.1551-2916.2005.00212.x

[16] L.A. Khalam, M.T. Sebastian, Effect of Cation Substitution and Non-Stoichiometry on the Microwave Dielectric Properties of Sr(B'0.5Ta0.5)O3 [B'=Lanthanides] Perovskites, J. Am. Ceram. Soc. 89 (2006) 3689-3695.

DOI: 10.1111/j.1551-2916.2006.01321.x

[17] C.L. Huang, M.H. Weng, Improved high q value of MgTiO3-CaTiO3 microwave dielectric ceramics at low sintering temperature, Materials Research Bull. 36 (2001) 2741-2750.

DOI: 10.1016/s0025-5408(01)00752-8

[18] W.W. Cho, K.I. Kakimoto and H.S. Ohsato, High-Q Microwave Dielectric SrTiO3-Doped MgTiO3 Materials with Near-Zero Temperature Coefficient of Resonant Frequency, Jpn. J. Appl. Phys. 43(2004) 6221-6224.

DOI: 10.1143/jjap.43.6221