Negatively charged hydrogen at oxygen-vacancy sites in BaTiO3: Density-functional calculation
Negatively charged hydrogen at oxygen-vacancy sites in BaTiO3: Density-functional calculation
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DOI：
10.1063/1.3483243
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发表时间：
2010-10-15
影响因子：
3.2
通讯作者：
Tsuneyuki, Shinji
中科院分区：
文献类型：
--
作者：
Iwazaki, Yoshiki;Suzuki, Toshimasa;Tsuneyuki, Shinji
通过第一性原理密度泛函理论计算，研究了钙钛矿型氧化物中H原子和氧空位（V-O）形成的缺陷在BaTiO 3中的稳定性和复杂缺陷形成过程的稳定价态.在我们的研究结果中，氢原子扩散质子（H+）到BaTiO 3的间隙网站，而这些原子被困在VO网站的中心转换为负离子化状态（H-）。我们还发现，H原子在V-O位的俘获只发生在n型富载流子环境中，而没有V-O（2+）和H+的载流子补偿。如果对载流子进行补偿，则由于H+离子与带正电的V-O（2+）位之间存在排斥库仑势，H+离子被排斥在V-O（2+）位之外。讨论了氢原子扩散能图计算中的困难，包括扩散过程中稳定价态的本质变化，并提出了一种实用的解决方案。(C)2010年美国物理学会。[doi：10.1063/1.3483243]
With a specific focus on defects formed from H atoms and oxygen vacancies (V-O) in perovskite-type oxide, stability and stable valence states of complex defects formation processes within BaTiO3 are studied by using first-principle density-functional theory calculations. In our findings, H atoms diffuse as protons (H+) into interstitial sites in BaTiO3, whereas these atoms when trapped at centers of VO sites convert to negatively ionized states (H-). We also find that H atom trapping at V-O sites occurs only in n-type carrier-rich environments without carrier compensation of V-O(2+) and H+. If carrier electrons are compensated, H+ ions are excluded from V-O(2+) sites due to the repulsive Coulomb potential existing between the H+ ion and the positively charged V-O(2+) site. Difficulties in the calculation of the diffusion-energy diagram for H atoms, involving essential changes in the stable valence states during the diffusion process, are discussed and a practical solution is presented. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3483243]