Cuong Do Duc, Lee Bora, Choi Kyeong Mi, Ahn Hyo-Shin, Han Seungwu, Lee Jaichan
School of Materials Science and Engineering, SungKyunKwan University, Suwon 440-746, Korea.
Phys Rev Lett. 2007 Mar 16;98(11):115503. doi: 10.1103/PhysRevLett.98.115503. Epub 2007 Mar 15.
We find, using a local density approximation +Hubbard U method, that oxygen vacancies tend to cluster in a linear way in SrTiO(3), a prototypical perovskite oxide, accompanied by strong electron localization at the 3d state of the nearby Ti transition metal ion. The vacancy clustering and the associated electron localization lead to a profound impact on materials properties, e.g., the reduction in free-carrier densities, the appearance of characteristic optical spectra, and the decrease in vacancy mobility. The high stability against the vacancy migration also suggests the physical reality of the vacancy cluster.
我们发现，使用局域密度近似+哈伯德U方法，在典型的钙钛矿氧化物SrTiO₃中，氧空位倾向于以线性方式聚集，同时在附近的Ti过渡金属离子的3d态存在强烈的电子局域化。空位聚集以及相关的电子局域化对材料性能产生了深远影响，例如自由载流子密度降低、特征光谱出现以及空位迁移率下降。对空位迁移的高稳定性也表明了空位簇的物理真实性。
