摘要
采用固相烧结法在空气中经1360℃制备了单相La_(1.5)Sr_(0.5)NiO_(4-δ)陶瓷,将其在2×10^(-3)Pa的真空度下于800℃退火3h;用阻抗分析仪对真空退火前后其变温交流阻抗谱进行了分析。结果表明:真空退火前的陶瓷在10~2～10~6Hz和100～320 K时存在高达10~5的巨介电常数,且与电荷有序有关;退火后介电常数减小到10~4,弥散区域向低频发生大幅移动,其极化以晶界极化为主。
The single phase La1.5Sr0.5NiO4-δ ceramic was prepared by solid sintering method at I 360 ℃ in air and then annealed at 800 ℃ for 3 h under vacuum of 2 × 10^-3 Pa. The AC impedance spectrum for variable temperature of the ceramic before and after vacuum annealing was analyzed by impedance analyzer. The results show that the large dielectric constant before vacuum annealing was about 105 under the conditions of 100-320 K and 102 -106 Hz and the large dielectric constant originated from charge-ordering. The dielectric constant reduced to 104 after annealing, meanwhile, the diffuse area shifted to low frequency radically, and the polarization mainly came from grain boundary polarization.
出处
《机械工程材料》
CAS
CSCD
北大核心
2011年第11期69-72,共4页
Materials For Mechanical Engineering
基金
国家自然科学基金资助项目(10704054)
关键词
巨介电常数
陶瓷
真空退火
large dielectric constant
ceramic
vacuum annealing
