Effect of BaCu(B₂O₅) Additive on the Sintering Temperature and Microwave Dielectric Properties of BaTi₄O₉ Ceramics

Abstract

BaCu(B 2 O 5 ) (BCB) additive was used to decrease the sintering temperature of the BaTi 4 O 9 ceramics. The amount of Ba 4 Ti 13 O 30 second phase increased with the addition of BCB, whereas that of the BaTi 4 O 9 phase decreased. The bulk density and dielectric constant (" r ) considerably increased with the addition of BCB. An increase in the Q-value was also observed for the BaTi 4 O 9 ceramics with a small amount of BCB. Good microwave dielectric properties with values of " r ¼ 32, Q Â f ¼ 10800 GHz and f ¼ 32 ppm/ C were obtained in the BaTi 4 O 9 ceramics with 12.0 mol % of BCB sintered at 875 C for 2 h.

Effect of B2O3 and CuO on the sintering temperature and microwave dielectric properties of the BaTi4O9 ceramics

“…When CuO was added to the BaTi 4 O 9 ceramics containing 2.0 mol% B 2 O 3 , they were able to be sintered at temperatures as low as 875 • C. Figure 4 shows the X-ray diffraction patterns of the BaTi 4 ceramics were well sintered even at 850 • C and had excellent microwave dielectric properties [12]. Therefore, it is considered that the BaCu(B 2 O 5 ) second phase is responsible for the densification of the CuO and B 2 O 3 added BaTi 4 O 9 ceramics at low temperature.…”

Low temperature sintering and microwave dielectric properties of BaO–0.6ZnO–2.9TiO2 ceramics using BaCu(B2O5) addition

“…x wt% BaCu(B 2 O 5 ) ceramics sintered at 900°C are shown in Fig. 2 [10,11]. Hence, we reported another possible phase BaTiO 3 in the BaCu(B 2 O 5 )-doped titanates ceramics.…”

Low-temperature sintering and microwave dielectric properties of BaO–0.15ZnO–4TiO2 ceramics with Li2O–B2O3–SiO2 addition

“…ZnO can effectively lower the sintering temperature and improve the microwave dielectric properties of the BaOTiO 2 ceramics [4][5][6][7]. The BaO-ZnO-TiO 2 system has four ternary phases: Ba 4 ZnTi 11 O 27 , BaZn 2 Ti 4 O 11 , Ba 2 ZnTi 5 O 13 and hollandite-type solid solutions (Ba x Zn x Ti 8-x O 16 ) [8], in which BaZn 2 Ti 4 O 11 sinters at 1200°C with microwave dielectric properties: e r = 30, Q 9 f = 68,000 GHz, and s f = -30 ppm/°C [6], and it may be added to offset the positive s f of some BaO-TiO 2 ceramics such as BaTi 4 O 9 and BaTi 5 O 11 . However, a sintering temperature of less than 950°C is generally required in LTCC technology, considering the melting temperature of Ag (961°C) that is usually used as the internal electrode.…”

“…On the one hand, addition of a sintering aid such as a low-melting glass or oxide with low melting point was considered to be a useful approach [9]. Many kinds of sintering aids, such as B 2 [15][16][17][18], have been added in BaTi 4 O 9 and BaO-ZnO-TiO 2 system to decrease the sintering temperature successfully, among which Li 2 O-B 2 O 3 -SiO 2 (LBS) glass is one of the widely used sintering aids [19,20]. For instance, Choi et al [14] used 10 wt% Li 2 O-B 2 O 3 -SiO 2 glass to decrease the sintering temperature of BaTi 4 O 9 to 875°C, and the microwave dielectric properties of the resulting ceramic are e r = 32, Q 9 f = 9000 GHz and s f = 10 ppm/°C.…”