晶格常数的变化对钛酸铝热稳定性的影响

Effect of Variation of Lattice Constants on the Thermal Stability of Aluminium Titanate

深入研究了晶格常数的变化和钛酸铝热稳定性的关系．通过仔细分析钛酸铝的晶格常数随温度变化的特点，发现钛酸铝的晶格常数Ｃ随温度升高而降低这一反常现象．提出了钛酸铝的稳定性与其晶格常数Ｃ的大小密切相关的论点．在钛酸铝中引入多种添加剂以改变其晶格常数．结果发现晶格常数Ｃ的大小反映了钛酸铝的稳定性．晶格常数Ｃ越大，钛酸铝就越稳定.钛酸铝稳定性提高的原因是：晶格常数ｃ对应于钛酸铝晶体结构中畸变的［ＭｅＯ6］八面体的高度，Ｃ值增大导致八面体的畸变程度降低，结果就使得钛酸铝更稳定．还研究了不同烧成工艺对钛酸铝的晶格常数和稳定性的影响,结果发现：随着烧成温度的提高和保温时间的延长，钛酸铝的晶格常数Ｃ增大，其稳定性也相应提高．

The relationship was investigated between lattice constants and thermal stability ofaluminium titanate (Al_2TiO_5). Through studying the variation of lattice constants of Al_2TiO_5 withtemperature, the authors discovered am abnormal phenomenon that lattice constant c of Al_2TiO_5decreases with the increase of temperature. The authors proposed that the thermal stability ofAl_2TiO_5 is closely related to its lattice constant c. Different additives were added to Al_2TiO_5 tochange its lattice constants. The stability of Al_2TiO_5 can be reflected by its lattice constant c.The larger lattice constant of the more stable aluminium titanate. Lattice constant c correspondsto the height of the distorted [MeO_6] octahedra in the crystal structure of Al_2TiO_5 and its increasewill lead to a reduction of distortion of the octahedra, so that the stability of Al_2TiO_5 is improved.The effect of firing process on lattice constants and stability of Al_2TiO_5 was also explored. Theresult shows that with increase of firing temperature and extension of soaking time, aluminiumtitanate exhibits larger lattice constant c and its stability increases correspondingly.