Investigation on electrical properties of wollastonite glass-ceramic and woilastonite glass-ceramic/TiO2 composites

摘要

In this investigation, wollastonite glass-ceramics and composites containing 80 wt% glass powder and 20 wt% second component (TiO2) were prepared via pressureless sintering. Firstly, the sinterability of the prepared samples of the glassy powder in the system (SiO2-CaO-Na2O-Fe2O3-WO3) was investigated in the temperature range of 720-900°C and soaking time of 180 min. Then, the influence of the increase in the glass powder particle size on the sinterability and dielectric properties of the glass-ceramic samples was studied. Finally, the composites were made of the mixture of glass powder and second component. It was observed that the increase of the glassy powder particle size improved the sinterability and dielectric properties of the glass-ceramic specimens. Wollastonite glass-ceramics with 16 jim particle size had the maximum constant and minimum loss (e,.=10-10 and tan5=0-005) compared with the other glass-ceramics. Precipitation oftitanite phase in the composite of wollastonite glass/TiO2 caused these samples have e_r=17-61 and tan5=0-0004.