Hydrothermal degradation of cubic zirconia
Hydrothermal degradation of cubic zirconia
复制标题
立方氧化锆的水热降解
DOI：
10.1016/s1359-6454(03)00362-8
复制
发表时间：
2003
期刊：
影响因子：
9.4
通讯作者：
Jiaqi He
中科院分区：
文献类型：
--
作者：
Xin Guo;Jiaqi He
当在相对较低的温度（65-400 °C）下退火时，四相ZrO 2在水或水蒸气的存在下经历四相到单斜相的转变;这种转变已被证明是由于氧空位的湮灭。然而，立方氧化锆一直被认为是稳定的类似条件下。然而，在2.6×10−2atm的蒸汽压下，在250 °C下退火2年后，8mol%Y2O3掺杂的立方ZrO 2陶瓷样品开裂。尽管样品相仍然主要是立方相，但随后的X射线衍射研究表明，实际上发生了一种相变，而TEM研究和电子衍射证明了单斜ZrO 2的沉淀。退火后，发现样品的电导率增加约30%，表明质子传导。这是首次观察到的立方氧化锆的水热降解。
Tetragonal ZrO2undergoes a tetragonal to monoclinic transformation with the presence of water or water vapor when annealed at relatively low temperatures (65–400 °C); such a transformation has been shown to be due to the annihilation of oxygen vacancies. Nevertheless, cubic ZrO2has always been presumed to be stable under similar conditions. However, after annealing at 250 °C under a vapor pressure of 2.6×10−2atm for 2 years, the 8 mol% Y2O3-doped cubic ZrO2ceramic samples cracked. Even though the sample phase was still predominantly cubic, subsequent X-ray diffraction studies indicated that a kind of phase transformation actually occurred, while TEM investigations and electron diffractions demonstrated the precipitation of monoclinic ZrO2. After annealing, the electrical conductivity of the sample was found to increase by about 30%, suggesting proton conduction. This is the first observation of the hydrothermal degradation in cubic ZrO2.