Effects of Rate-Controlled Sintering on Phase Formation, Dielectric and Ferroelectric Properties of Cobalt Oxide Doped BNKT Ceramics

摘要

Lead-free powders of Bi(Na_(0.81)K_(0.19))O_3 doped 0.3 wt.% CoO were prepared using a simple conventional mixed oxide technique. The heating rate during sintering process was controlled with various rates up temperature. The samples were sintered at 1,050°C and the dwelling time for 4 h which difference heating rate controlled i.e. 100, 300, and 600°C/h. The XRD pattern analysis of all studied samples showed a single phase perovskite structure. Dielectric constant value at higher than 200°C of studied samples increased as a function of the rate controlled sintering temperature as well as ferroelectric properties at room temperature. The heating rate at 600°C/h sample showed maximum dielectric constant (～5961) at T_m. In addition, the ferroelectric properties were analyzed and discussed.