摘要
采用第一性原理对掺杂Sm2O3的Ba0.5Sr0.5Co0.75Fe0.25O3-δ体系的电子结构和空位形成能进行了研究。研究结果表明,Co和Sm的态密度在费米能级附近有较大的态,而Fe则很小,这使得Co和Sm离子易于变价,而Fe离子的化合价则基本保持不变。空位形成能随空位数的增多而增大,Sm的掺杂有利于氧空位的形成,且CoVFe比CoVCo型氧空位形成能稍大,这些源于体系的电子结构和局域几何结构。
The electronic structures and vacancy formation energies of the Ba0.5Sr0.5Co0.75Fe0.25O3-δ system doped with Sm2O3 were studied by using the first principle.The calculated results show that the densities of states for Co and Sm in the system are large at the Fermi level,nevertheless it is small for Fe,which makes the variability of the valence of Co and Sm and the maintenance for Fe.The vacancy formation energies increase with an increase in the vacancy numbers.It is favorable for the formation of the oxygen vacancy when Sm2O3 is doped in the system,and compared to the model CoVCo,the model CoVFe＇s vacancy energy is slightly larger,related with the electronic structures and the local geometric structures.
出处
《稀土》
EI
CAS
CSCD
北大核心
2012年第5期37-42,共6页
Chinese Rare Earths
基金
内蒙古科技大学创新基金(2009NC008)
教育部春晖计划项目资助(Z2009-1-01050)
