掺杂钙钛矿型氧化物的固体结构及其可交换氧

The Structure and Labile Oxygen of Impurity-doped Perovskite-type Oxide

钙钛矿型氧化物具有稳定的立方结构，以不同价态元素（V5＋，Al3＋，Mg2＋，Li＋）对SrTiO3中的Ti4＋进行取代，XRD表明其基本结构保持不变，同时其谱线有不同程度的宽化．这种宽化归因于取代所引起的晶体不完整性．取代元素的价态及量将在不同程度上破坏晶体的完整性．这种不完整性导至氧空位V的形成，从而可使晶格氧与气相氧在较低温度进行交换，TPD显示300～600℃的可交换氧量决定于取代引起的晶体不完整性．

Perovskite type oxide has a stable cubic structure. XRD pattern showed that the fundamental structure of SrTiO3 is unchanged by adding various valent elements(V5+,Al3+, Mg2+, Li1+) partially substituting for Ti4+ in SrTiO3. But the widening of XRD line proved that more crystalline imperfections are formed by doping. The lower of the valence and the larger amount of the dopant added, the stronger is the effect resulted.The crystalline imperfection induces the formation of oxygen vacancy V6 whereby the lattice oxygen becomes exchangeable with the oxygen gas at moderate temperature. TPD showed that the amount oflabile oxygen at 300 ~ 600℃ was closely related to the degree of crystailine twerfection in doped SrTiO3.