SYNTHESIS OF AG(NB_(0.8) TA_(0.2)) O_3 CERAMICS UNDER DIFFERENT AMBIENT CONDITIONS

Different ambient conditions for the synthesis of Ag（Nb0.8Ta0.2）O3 ceramics were investi- gated. The Ag（Nb0.8Ta0.2）O3 powder was synthesized at 950 ℃ under different ambient conditions, and then pressed into disks and sintered between 1060 ℃ and 1100 ℃ respectively. Samples were investigated by X-ray diffraction, scanning electron microscopy and dielectric measurement. The results show that perovskite Ag（Nb0.8Ta0.2）O3 powder was easier to be synthesized in air than in vacuum at 950℃. Grain size of ceramic samples sintered in air was uniform （about 1 μm） and its dielectric loss was small for its high density. However, the samples decomposed greatly and ceramics could hardly be densified when sintered in vacuum, Thus,. higher atmospheric pressure and oxygen atmosphere would benifit the synthesis of Ag （Nb0.8Ta0.2）O3, and suppress its decomposition at high temperature.

为 Ag (Nb_(0.8 )Ta_(0.2 )) 的合成的不同周围的条件 O_3ceramics 被调查。Ag (Nb_(0.8 )Ta_(0.2 )) O_3 粉末在不同周围的条件下面在 950 deg C 被综合，然后分别地压了进在 1 060 deg C 和 1100deg C 之间的磁盘和 sintered。样品被 X 光检查衍射调查，扫描电子显微镜学和绝缘的测量。结果显示出 O_3 粉末是的那 perovskite Ag (Nb_(0.8 )Ta_(0.2 )) 对更容易在 950 deg C 比在真空在空中被综合。在空中的陶器的样品 sintered 的谷物尺寸是制服(大约 1 亩 m ) ，它的绝缘的损失为它的高密度是小的。然而，极大地分解的样品和陶艺几乎不能被使增加密度什么时候在真空的 sintered。因此，更高的气压和氧空气将 benifit Ag (Nb_(0.8 )Ta_(0.2 )) 的合成 O_3，并且在高温度压制它的分解。