Microwave Dielectric Properties of (Ba_0.1Mg_0.9)(A_0.05Ti_0.95)O₃ (A = Zr, Sn) Ceramics

Abstract

Microwave dielectric ceramic materials based on (Ba_0.1Mg_0.9)(A_0.05Ti_0.95)O₃ (A = Zr, Sn) were synthesized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and their microwave dielectric properties were investigated. In the system, the substitution Zr and Sn for Ti is effective for dielectric constant and Q × f values up to 73,000 (GHz). Two Ba₂Ti₉O₂₀ and BaTi₅O₁₁ second phases formed and significantly affected the microwave dielectric properties. With Zr and Sn additives, the densification temperature of (Ba_0.1Mg_0.9)(A_0.05Ti_0.95)O₃ (A = Zr, Sn) ceramics can be effectively reduced to1210°C. The dielectric constant of (Ba_0.1Mg_0.9)(Zr_0.05Ti_0.95)O₃ (hereafter referred to as BMZT) sintered at 1210°C/4h is 20.6, the Q × f value is 112,000GHz and the temperature coefficient of resonant frequency (τ _f ) is -50 ppm/°C. (Ba_0.1Mg_0.9)(Sn_0.05Ti_0.95)O₃ (hereafter referred to as BMST) sintered at 1210°C/4h has ϵ_r of 20.4, Q × f value of 73,000 GHz and τ _f of −61.5 ppm/°C.

Keywords:

• (Ba_0.1Mg_0.9)(A_0.05Ti_0.95)O₃ (A = Zr, Sn) ceramics
• microwave dielectric properties

Acknowledgment

This work was supported by the National Science Council of the Republic of China under grant NSC101-2622-E-239-002-CC3.