| Summary: | 碩士 === 國立臺灣大學 === 材料科學與工程學研究所 === 92 === Synthesis of La2O3-SiO2-B2O3 (LSB) based glass-ceramic composites using glass melting and tape-casting methods of glass powder/filler has been conducted in this study. The LSB mixture could be melted homogeneously at 1300oC. XRD result showed that some LSB glass systems were entirely amorphous. Among those glasses, LSB3 glass (molar ratio: La2O 3 22%, SiO2 10%, B2O3 68%) showed a superior sintering ability (∆T=115oC). The LSB/mullite (LSBM) glass-ceramics (with a mass ratio of 60/40) composite could be sintered at a low temperature of 760oC, giving an optimal sintered density of 3.39 g/cm3, and porosity less than 0.5 %, which matched the requirements for the low-temperature-cofired- ceramics (LTCC) application. Moreover, dispersive behavior of the L3 glass powder with six kinds of commercial dispersants in MEK and toluene solvents had been studied. Toluene and RE-610 (with an addition of 1.0 mass % to the glass) were found to be the optimal system to L3 glass powder. Furthermore, the investigation on crystal phase formation and microstructure analysis of the LSBM was conducted. LSBM system had two crystal phases, including flaky LaBO(SiO4) crystals and bulky crystalline LaB3O6 grains when sintered above 840oC for 1 h, while the LaBO3 crystal phase was a transient phase between 800oC and 840oC. The dielectric constant (��), and dielectric loss (tan ��) of the LSBM glass-ceramics increased as the content of L3 glass increased. The LSBM (60/40) glass-ceramic composites showed superior �� and tan �� properties of 4.85 and 2.4×10-3, respectively at 1 GHz.
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