A New System of Low Temperature Sintering ZnO–SiO₂ Dielectric Ceramics

Abstract

A new ZnO–SiO2 microwave dielectric ceramic system with Li2CO3 and Bi2O3 composite additives was studied. It was difficult to acquire dense ceramics at 1380 °C without sintering aids using the ZnO–SiO2 system. With 5 wt % Li2CO3 and 4 wt % Bi2O3 composite addition, the ZnO–SiO2 system can be sintered well at approximately 900 °C. The dielectric constant of ZnO–SiO2 system decreased with increasing SiO2 content and Q×f value acquired a maximum at a certain SiO2 content. The samples of ZnO–0.6SiO2 with Li2CO3 and Bi2O3 addition sintered at 910 °C for 2 h showed excellent properties such as εr=6.65, Q×f=33,000 GHz (at 11 GHz), and τf=-70 ppm/°C.

Experimental determination of the liquidus temperatures of the binary (SiO2–ZnO) system in equilibrium with air

“…SiO 2 -ZnO contained glass-ceramics are one of the most important materials due to their electrical, optical and physical properties [1][2][3]. Glass-ceramics with ZnO are promising candidates in phosphors [4,5], industrial glazes [6].…”

MICROSTRUCTURE, PHASE EVOLUTION, AND MICROWAVE DIELECTRIC PROPERTIES OF Li₂O AND Ga₂O ₃ DOPED ZINC ORTHOSILICATE

“…As shown in Table 1, the addition of various sintering aids allows to lower the sintering temperature of zinc orthosilicate based ceramics [6][7][8][9][10][11][12][13][14][15][16][17][18].…”

A Low Sintering Temperature Low Loss Microwave Dielectric Material ZnZrNb2O8

“…Several microwave dielectric ceramic systems such as Li 2 WO 4 , Li 2 O‐MO‐MoO 3 (M = Zn, Ca, Al, In), AMoO 4 (A = Mg, Zn, Mn), ZnO‐SiO 2 , Li 2 O‐Nb 2 O 5 ‐TiO 2 , BaO‐TiO 2 ‐TeO 2 , etc. have been reported as intrinsic low sintering temperature materials . But the Qf value of these materials need to be improved when the dielectric constant is around 30—BaTiTe 3 O 9 has ε of 29 with Qf of 1700 GHz, Bi 12 GeO 20 has ε of 38 with Qf of 7800 GHz, and Bi 12 SiO 20 has ε of 37.6 with Qf of 8100 GHz …”

“…2,5 Therefore, numerous glass ceramic-based LTCC dielectric materials have been developed and commercialized, but there is still a preference for developing phase-pure compositions to minimize dielectric loss, especially for microwave applications. 6 [6][7][8][9][10][11][12][13][14] But the Qf value of these materials need to be improved when the dielectric constant is around 30-BaTiTe 3 O 9 has e of 29 with Qf of 1700 GHz, 13 Bi 12 GeO 20 has e of 38 with Qf of 7800 GHz, and Bi 12 SiO 20 has e of 37.6 with Qf of 8100 GHz. 14 In this communication, a low sintering temperature microwave dielectric material with high Qf value is reported.…”