Dielectric properties of B₂O₃ doped MgTiO₃-CaTiO₃ system ceramics

Abstract

The dielectric ceramics with a main crystal phase of MgTiO₃ and additional crystal phase of CaTiO₃ were prepared by the conventional electronic ceramics technology. The structures of MgTiO₃ are ilmenite-type, and belong to hexagonal syngony. The ratio of MgTiO₃ to CaTiO₃ can be adjusted to gain a zero temperature coefficient of ɛ and a higher ɛ for the system. The effects of B₂O₃ doping on the dielectric properties of MgTiO₃-CaTiO₃ (MCT) ceramics were investigated. The addition of B₂O₃ decreases the sintering temperature and results in rapid densification without obvious negative effect on the Q values of the system (Q=1/tan δ). B₂O₃ exists as liquid phase in the sintering process, promoting the reactions as a sintering agent.

Keywords

MgTiO₃ / CaTiO₃ / MCT / dielectric properties / B₂O₃ doping

References

[1] Ferreira V M, Azough F, Baptista J L, . Magnesium Titanate Microwave Dielectric Ceramics. Ferroelectric, 1992, 133: 127-127.

[2] Ferreira V M, Baptista J L, Kamba L, . Dielectric Spctroscopy of MgTiO₃-based Ceramics in the 109-1014Hz Region. J. Mater. Soc., 1993, 28: 5894-5894.

[3] Ferreira V M, Azough F, Freer R, . The Effect of Cr and La on MgTiO₃-CaTiO₃ Microwave Dielectric Ceramics. J. Mater. Res., 1997, 12: 3293-3293.

[4] Hakki B W, Coleman P D. A Dielectric Resonator Method of Measuring Inductive Capacities in the Millimeter Range. IEEE Trans. Microwave Theory Technol., 1960, 8: 402-402.

[5] Huang Chengliang, Weng Ming-Hun. Improved HighQ value of MgTiO₃-CaTiO₃ Microwave Dielectric Ceramics at Low Sintering Temperature. Mater. Res. Bul., 2001, 336: 2741-2741.