关键词: 钇, 钛酸钡, 非均匀形核, 表面包覆, 电阻率

Abstract:

Y-doped nano-crystalline barium titanate （Y-BT） powders were prepared via the heterogeneous-nucleation surface-coating method and the chemical-mixing method, respectively. The prepared powders and the sintered ceramic samples were then characterized by means of differential scanning calorimetry, thermogravimetry, induc- tively-coupled plasma-atomic emission spectrometry and scanning electron microscopy. Moreover, the effect of Y dosage on the room-temperature resistivity of the Y-BT ceramics prepared with different methods was discussed. The results show that, as compared with the Y-BT powders prepared via the chemical mixing method, the powders pre- pared via the coating method have more homogeneous Y distribution, more uniform crystal size and more accurate stoichiometric ratio, and that the corresponding Y-BT ceramic possesses good semiconducting properties at a Y dosage of only 0. 1% and achieves more minimum room-temperature resistivity at a low temperature.

Key words: yttrium, barium titanate, heterogeneous nucleation, surface coating, resistivity