Abstract:

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 Vo whereby the lattice oxygen becomes exchangeable with the oxygen gas at moderate temperature. TPD showed that the amount of labile oxygen at 300~600℃ was closely related to the degree of crystailine imperfection in doped SrTiO3.

Key words: Perovskite, Substituting, XRD line widening, Crystalline imperfection, Labile oxygen